previously we barfed on function type definition with optional arguments
like {function(number=)}

this fixes it

I also added a bunch of code that helps to debug incorrectly parsed docs.

we now have two types of namespaces:

- true namespace: angular.* - used for all global apis
- virtual namespace: ng.*, ngMock.*, ... - used for all DI modules

the virual namespaces have services under the second namespace level (e.g. ng.)
and filters and directives prefixed with filter: and directive: respectively
(e.g. ng.filter:orderBy, ng.directive:ngRepeat)

this simplifies urls and makes them a lot shorter while still avoiding name collisions