remove _null and _undefined

they have no significant effect on minified and gziped size. in fact
they make things worse.

file        | before     | after removal
----------------------------------------
concat      | 325415     | 325297
min         | 62070      | 62161
min + gzip  | 25187      | 25176

The bottom line is that we are getting 0.05% decrease in size after
gzip without all of the hassle of using underscores everywhere.

22 files changed, 52 insertions, 54 deletions

diff --git a/src/Angular.js b/src/Angular.js
index a91bf04c..b2949646 100644
--- a/src/Angular.js
+++ b/src/Angular.js
@@ -52,9 +52,7 @@ if ('i' !== 'I'.toLowerCase()) {
 function fromCharCode(code) { return String.fromCharCode(code); }
 
 
-var _undefined        = undefined,
-    _null             = null,
-    $$element         = '$element',
+var $$element         = '$element',
     $$update          = '$update',
     $$scope           = '$scope',
     $$validate        = '$validate',
@@ -315,7 +313,7 @@ function isDefined(value){ return typeof value != $undefined; }
  * @param {*} value Reference to check.
  * @returns {boolean} True if `value` is an `Object` but not `null`.
  */
-function isObject(value){ return value!=_null && typeof value == $object;}
+function isObject(value){ return value!=null && typeof value == $object;}
 
 
 /**
diff --git a/src/Browser.js b/src/Browser.js
index e51df16c..55439762 100644
--- a/src/Browser.js
+++ b/src/Browser.js
@@ -95,7 +95,7 @@ function Browser(window, document, body, XHR, $log) {
       var script = jqLite('<script>')
           .attr({type: 'text/javascript', src: url.replace('JSON_CALLBACK', callbackId)});
       window[callbackId] = function(data){
-        window[callbackId] = _undefined;
+        window[callbackId] = undefined;
         script.remove();
         completeOutstandingRequest(callback, 200, data);
       };
@@ -290,7 +290,7 @@ function Browser(window, document, body, XHR, $log) {
     var cookieLength, cookieArray, cookie, i, keyValue, index;
 
     if (name) {
-      if (value === _undefined) {
+      if (value === undefined) {
         rawDocument.cookie = escape(name) + "=;expires=Thu, 01 Jan 1970 00:00:00 GMT";
       } else {
         if (isString(value)) {
diff --git a/src/Compiler.js b/src/Compiler.js
index 09857ea4..a03d24c4 100644
--- a/src/Compiler.js
+++ b/src/Compiler.js
@@ -330,7 +330,7 @@ Compiler.prototype = {
         template.addChild(i, self.templatize(child, i, priority));
       });
     }
-    return template.empty() ? _null : template;
+    return template.empty() ? null : template;
   }
 };
 
diff --git a/src/JSON.js b/src/JSON.js
index 52d5a763..5e13dc45 100644
--- a/src/JSON.js
+++ b/src/JSON.js
@@ -15,7 +15,7 @@ var array = [].constructor;
  */
 function toJson(obj, pretty) {
   var buf = [];
-  toJsonArray(buf, obj, pretty ? "\n  " : _null, []);
+  toJsonArray(buf, obj, pretty ? "\n  " : null, []);
   return buf.join('');
 }
 
@@ -87,7 +87,7 @@ function toJsonArray(buf, obj, pretty, stack) {
     }
     stack.push(obj);
   }
-  if (obj === _null) {
+  if (obj === null) {
     buf.push($null);
   } else if (obj instanceof RegExp) {
     buf.push(angular['String']['quoteUnicode'](obj.toString()));
@@ -128,7 +128,7 @@ function toJsonArray(buf, obj, pretty, stack) {
       var childPretty = pretty ? pretty + "  " : false;
       var keys = [];
       for(var k in obj) {
-        if (obj[k] === _undefined)
+        if (obj[k] === undefined)
           continue;
         keys.push(k);
       }
diff --git a/src/Resource.js b/src/Resource.js
index f748fb5a..341193fa 100644
--- a/src/Resource.js
+++ b/src/Resource.js
@@ -128,7 +128,7 @@ ResourceFactory.prototype = {
         default:
           throw "Expected between 1-2 arguments [params, callback], got " + arguments.length + " arguments.";
         }
-        var data = isPostOrPut ? this : _undefined;
+        var data = isPostOrPut ? this : undefined;
         Resource[name].call(this, params, data, callback);
       };
     });
diff --git a/src/Scope.js b/src/Scope.js
index 7d802a51..c5612c9f 100644
--- a/src/Scope.js
+++ b/src/Scope.js
@@ -15,7 +15,7 @@ function getter(instance, path, unboundFn) {
     if (isUndefined(instance)  && key.charAt(0) == '$') {
       var type = angular['Global']['typeOf'](lastInstance);
       type = angular[type.charAt(0).toUpperCase()+type.substring(1)];
-      var fn = type ? type[[key.substring(1)]] : _undefined;
+      var fn = type ? type[[key.substring(1)]] : undefined;
       if (fn) {
         instance = bind(lastInstance, fn, lastInstance);
         return instance;
diff --git a/src/apis.js b/src/apis.js
index 1ca33208..9311c620 100644
--- a/src/apis.js
+++ b/src/apis.js
@@ -1,6 +1,6 @@
 var angularGlobal = {
   'typeOf':function(obj){
-    if (obj === _null) return $null;
+    if (obj === null) return $null;
     var type = typeof obj;
     if (type == $object) {
       if (obj instanceof Array) return $array;
diff --git a/src/directives.js b/src/directives.js
index 5e611571..32860a1e 100644
--- a/src/directives.js
+++ b/src/directives.js
@@ -202,7 +202,7 @@ angularDirective("ng:bind", function(expression, element){
     var lastValue = noop, lastError = noop;
     this.$onEval(function() {
       var error, value, html, isHtml, isDomElement,
-          oldElement = this.hasOwnProperty($$element) ? this.$element : _undefined;
+          oldElement = this.hasOwnProperty($$element) ? this.$element : undefined;
       this.$element = element;
       value = this.$tryEval(expression, function(e){
         error = formatError(e);
@@ -229,7 +229,7 @@ angularDirective("ng:bind", function(expression, element){
           element.html('');
           element.append(value);
         } else {
-          element.text(value == _undefined ? '' : value);
+          element.text(value == undefined ? '' : value);
         }
       }
     }, element);
@@ -257,7 +257,7 @@ function compileBindTemplate(template){
     });
     bindTemplateCache[template] = fn = function(element, prettyPrintJson){
       var parts = [], self = this,
-         oldElement = this.hasOwnProperty($$element) ? self.$element : _undefined;
+         oldElement = this.hasOwnProperty($$element) ? self.$element : undefined;
       self.$element = element;
       for ( var i = 0; i < bindings.length; i++) {
         var value = bindings[i].call(self, element);
@@ -767,7 +767,7 @@ angularDirective("ng:style", function(expression, element){
     this.$onEval(function(){
       var style = this.$eval(expression) || {}, key, mergedStyle = {};
       for(key in style) {
-        if (resetStyle[key] === _undefined) resetStyle[key] = '';
+        if (resetStyle[key] === undefined) resetStyle[key] = '';
         mergedStyle[key] = style[key];
       }
       for(key in resetStyle) {
diff --git a/src/formatters.js b/src/formatters.js
index a7a5cc4f..02773be1 100644
--- a/src/formatters.js
+++ b/src/formatters.js
@@ -1,6 +1,6 @@
 function formatter(format, parse) {return {'format':format, 'parse':parse || format};}
 function toString(obj) {
-  return (isDefined(obj) && obj !== _null) ? "" + obj : obj;
+  return (isDefined(obj) && obj !== null) ? "" + obj : obj;
 }
 
 var NUMBER = /^\s*[-+]?\d*(\.\d*)?\s*$/;
@@ -94,8 +94,8 @@ angularFormatter['boolean'] = formatter(toString, toBoolean);
    </doc:example>
  */
 angularFormatter.number = formatter(toString, function(obj){
-  if (obj == _null || NUMBER.exec(obj)) {
-    return obj===_null || obj === '' ? _null : 1*obj;
+  if (obj == null || NUMBER.exec(obj)) {
+    return obj===null || obj === '' ? null : 1*obj;
   } else {
     throw "Not a number";
   }
diff --git a/src/jqLite.js b/src/jqLite.js
index cda8ec70..9c96df4a 100644
--- a/src/jqLite.js
+++ b/src/jqLite.js
@@ -105,7 +105,7 @@ function JQLiteData(element, key, value) {
     }
     cache[key] = value;
   } else {
-    return cache ? cache[key] : _null;
+    return cache ? cache[key] : null;
   }
 }
 
diff --git a/src/markups.js b/src/markups.js
index 99e1cca7..24de5c37 100644
--- a/src/markups.js
+++ b/src/markups.js
@@ -20,11 +20,11 @@ function parseBindings(string) {
 
 function binding(string) {
   var binding = string.replace(/\n/gm, ' ').match(/^\{\{(.*)\}\}$/);
-  return binding ? binding[1] : _null;
+  return binding ? binding[1] : null;
 }
 
 function hasBindings(bindings) {
-  return bindings.length > 1 || binding(bindings[0]) !== _null;
+  return bindings.length > 1 || binding(bindings[0]) !== null;
 }
 
 angularTextMarkup('{{}}', function(text, textNode, parentElement) {
diff --git a/src/parser.js b/src/parser.js
index a8bd21e4..0a19dad9 100644
--- a/src/parser.js
+++ b/src/parser.js
@@ -1,5 +1,5 @@
 var OPERATORS = {
-    'null':function(self){return _null;},
+    'null':function(self){return null;},
     'true':function(self){return true;},
     'false':function(self){return false;},
     $undefined:noop,
@@ -566,7 +566,7 @@ function parser(text, json){
       function (self){
         var o = obj(self);
         var i = indexFn(self);
-        return (o) ? o[i] : _undefined;
+        return (o) ? o[i] : undefined;
       }, {
         assign:function(self, value){
           return obj(self)[indexFn(self)] = value;
diff --git a/src/service/cookies.js b/src/service/cookies.js
index b8de81c2..86e55fc1 100644
--- a/src/service/cookies.js
+++ b/src/service/cookies.js
@@ -52,7 +52,7 @@ angularServiceInject('$cookies', function($browser) {
     //delete any cookies deleted in $cookies
     for (name in lastCookies) {
       if (isUndefined(cookies[name])) {
-        $browser.cookies(name, _undefined);
+        $browser.cookies(name, undefined);
       }
     }
 
diff --git a/src/service/hover.js b/src/service/hover.js
index a7cef71a..fca18130 100644
--- a/src/service/hover.js
+++ b/src/service/hover.js
@@ -50,7 +50,7 @@ angularServiceInject("$hover", function(browser, document) {
       }
     } else if (tooltip) {
       tooltip.callout.remove();
-      tooltip = _null;
+      tooltip = null;
     }
   });
 }, ['$browser', '$document'], true);
diff --git a/src/service/location.js b/src/service/location.js
index 31323284..a5875b72 100644
--- a/src/service/location.js
+++ b/src/service/location.js
@@ -199,7 +199,7 @@ angularServiceInject("$location", function($browser) {
    */
   function composeHref(loc) {
     var url = toKeyValue(loc.search);
-    var port = (loc.port == DEFAULT_PORTS[loc.protocol] ? _null : loc.port);
+    var port = (loc.port == DEFAULT_PORTS[loc.protocol] ? null : loc.port);
 
     return loc.protocol  + '://' + loc.host +
           (port ? ':' + port : '') + loc.path +
@@ -233,7 +233,7 @@ angularServiceInject("$location", function($browser) {
       loc.href = href.replace(/#$/, '');
       loc.protocol = match[1];
       loc.host = match[3] || '';
-      loc.port = match[5] || DEFAULT_PORTS[loc.protocol] || _null;
+      loc.port = match[5] || DEFAULT_PORTS[loc.protocol] || null;
       loc.path = match[6] || '';
       loc.search = parseKeyValue(match[8]);
       loc.hash = match[10] || '';
diff --git a/src/service/route.js b/src/service/route.js
index 2de484f6..19fc81bf 100644
--- a/src/service/route.js
+++ b/src/service/route.js
@@ -196,14 +196,14 @@ angularServiceInject('$route', function(location, $updateView) {
       });
       if (dstName) this.$set(dstName, dst);
     }
-    return match ? dst : _null;
+    return match ? dst : null;
   }
 
 
   function updateRoute(){
     var childScope, routeParams, pathParams, segmentMatch, key, redir;
 
-    $route.current = _null;
+    $route.current = null;
     forEach(routes, function(rParams, rPath) {
       if (!pathParams) {
         if (pathParams = matcher(location.hashPath, rPath)) {
@@ -213,7 +213,7 @@ angularServiceInject('$route', function(location, $updateView) {
     });
 
     // "otherwise" fallback
-    routeParams = routeParams || routes[_null];
+    routeParams = routeParams || routes[null];
 
     if(routeParams) {
       if (routeParams.redirectTo) {
diff --git a/src/service/xhr.bulk.js b/src/service/xhr.bulk.js
index 9933aa7e..c6cf608c 100644
--- a/src/service/xhr.bulk.js
+++ b/src/service/xhr.bulk.js
@@ -16,7 +16,7 @@ angularServiceInject('$xhr.bulk', function($xhr, $error, $log){
   function bulkXHR(method, url, post, callback) {
     if (isFunction(post)) {
       callback = post;
-      post = _null;
+      post = null;
     }
     var currentQueue;
     forEach(bulkXHR.urls, function(queue){
diff --git a/src/service/xhr.cache.js b/src/service/xhr.cache.js
index e87b127b..284321d7 100644
--- a/src/service/xhr.cache.js
+++ b/src/service/xhr.cache.js
@@ -26,7 +26,7 @@ angularServiceInject('$xhr.cache', function($xhr, $defer, $log){
   function cache(method, url, post, callback, verifyCache){
     if (isFunction(post)) {
       callback = post;
-      post = _null;
+      post = null;
     }
     if (method == 'GET') {
       var data, dataCached;
diff --git a/src/service/xhr.js b/src/service/xhr.js
index 1de72b22..18f695e6 100644
--- a/src/service/xhr.js
+++ b/src/service/xhr.js
@@ -129,7 +129,7 @@ angularServiceInject('$xhr', function($browser, $error, $log, $updateView){
   return function(method, url, post, callback){
     if (isFunction(post)) {
       callback = post;
-      post = _null;
+      post = null;
     }
     if (post && isObject(post)) {
       post = toJson(post);
diff --git a/src/validators.js b/src/validators.js
index ad76646b..c2902849 100644
--- a/src/validators.js
+++ b/src/validators.js
@@ -1,5 +1,5 @@
 extend(angularValidator, {
-  'noop': function() { return _null; },
+  'noop': function() { return null; },
 
   /**
    * @workInProgress
@@ -42,7 +42,7 @@ extend(angularValidator, {
       return msg ||
         "Value does not match expected format " + regexp + ".";
     } else {
-      return _null;
+      return null;
     }
   },
 
@@ -94,7 +94,7 @@ extend(angularValidator, {
       if (typeof min != $undefined && num > max) {
         return "Value can not be greater than " + max + ".";
       }
-      return _null;
+      return null;
     } else {
       return "Not a number";
     }
@@ -144,7 +144,7 @@ extend(angularValidator, {
     if (!("" + value).match(/^\s*[\d+]*\s*$/) || value != Math.round(value)) {
       return "Not a whole number";
     }
-    return _null;
+    return null;
   },
 
   /**
@@ -182,7 +182,7 @@ extend(angularValidator, {
             date.getFullYear() == fields[3] &&
             date.getMonth() == fields[1]-1 &&
             date.getDate() == fields[2])
-              ? _null 
+              ? null
               : "Value is not a date. (Expecting format: 12/31/2009).";
   },
 
@@ -215,7 +215,7 @@ extend(angularValidator, {
    */
   'email': function(value) {
     if (value.match(/^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}$/)) {
-      return _null;
+      return null;
     }
     return "Email needs to be in username@host.com format.";
   },
@@ -249,10 +249,10 @@ extend(angularValidator, {
    */
   'phone': function(value) {
     if (value.match(/^1\(\d\d\d\)\d\d\d-\d\d\d\d$/)) {
-      return _null;
+      return null;
     }
     if (value.match(/^\+\d{2,3} (\(\d{1,5}\))?[\d ]+\d$/)) {
-      return _null;
+      return null;
     }
     return "Phone number needs to be in 1(987)654-3210 format in North America or +999 (123) 45678 906 internationaly.";
   },
@@ -286,7 +286,7 @@ extend(angularValidator, {
    */
   'url': function(value) {
     if (value.match(/^(ftp|http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?$/)) {
-      return _null;
+      return null;
     }
     return "URL needs to be in http://server[:port]/path format.";
   },
@@ -322,7 +322,7 @@ extend(angularValidator, {
   'json': function(value) {
     try {
       fromJson(value);
-      return _null;
+      return null;
     } catch (e) {
       return e.toString();
     }
diff --git a/src/widgets.js b/src/widgets.js
index 91b0fcf2..ac8a88e0 100644
--- a/src/widgets.js
+++ b/src/widgets.js
@@ -148,7 +148,7 @@ function modelAccessor(scope, element) {
         return scope.$eval(expr);
       },
       set: function(value) {
-        if (value !== _undefined) {
+        if (value !== undefined) {
           return scope.$tryEval(function(){
             assign(scope, value);
           }, element);
@@ -310,7 +310,7 @@ function valueAccessor(scope, element) {
   return {
     get: function(){
       if (lastError)
-        elementError(element, NG_VALIDATION_ERROR, _null);
+        elementError(element, NG_VALIDATION_ERROR, null);
       try {
         var value = parse(scope, element.val());
         validate();
@@ -333,13 +333,13 @@ function valueAccessor(scope, element) {
   function validate() {
     var value = trim(element.val());
     if (element[0].disabled || element[0].readOnly) {
-      elementError(element, NG_VALIDATION_ERROR, _null);
+      elementError(element, NG_VALIDATION_ERROR, null);
       invalidWidgets.markValid(element);
     } else {
       var error, validateScope = inherit(scope, {$element:element});
       error = required && !value
               ? 'Required'
-              : (value ? validator(validateScope, value) : _null);
+              : (value ? validator(validateScope, value) : null);
       elementError(element, NG_VALIDATION_ERROR, error);
       lastError = error;
       if (error) {
@@ -367,7 +367,7 @@ function radioAccessor(scope, element) {
   var domElement = element[0];
   return {
     get: function(){
-      return domElement.checked ? domElement.value : _null;
+      return domElement.checked ? domElement.value : null;
     },
     set: function(value){
       domElement.checked = value == domElement.value;
@@ -425,7 +425,7 @@ var textWidget = inputWidget('keydown change', modelAccessor, valueAccessor, ini
       'image':           buttonWidget,
       'checkbox':        inputWidget('click', modelFormattedAccessor, checkedAccessor, initWidgetValue(false)),
       'radio':           inputWidget('click', modelFormattedAccessor, radioAccessor, radioInit),
-      'select-one':      inputWidget('change', modelAccessor, valueAccessor, initWidgetValue(_null)),
+      'select-one':      inputWidget('change', modelAccessor, valueAccessor, initWidgetValue(null)),
       'select-multiple': inputWidget('change', modelAccessor, optionsAccessor, initWidgetValue([]))
 //      'file':            fileWidget???
     };
@@ -448,9 +448,9 @@ function radioInit(model, view, element) {
  input.checked = false;
  input.name = this.$id + '@' + input.name;
  if (isUndefined(modelValue)) {
-   model.set(modelValue = _null);
+   model.set(modelValue = null);
  }
- if (modelValue == _null && viewValue !== _null) {
+ if (modelValue == null && viewValue !== null) {
    model.set(viewValue);
  }
  view.set(modelValue);
diff --git a/test/widgetsSpec.js b/test/widgetsSpec.js
index dc7ffa77..eab5cce7 100644
--- a/test/widgetsSpec.js
+++ b/test/widgetsSpec.js
@@ -682,7 +682,7 @@ describe("widget", function(){
       } else {
 
         event = document.createEvent('MouseEvent');
-        event.initMouseEvent('click', true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, _null);
+        event.initMouseEvent('click', true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
 
         event.preventDefaultOrg = event.preventDefault;
         event.preventDefault = function() {