Add `devel` to the DSL, + stable and bottle blocks

This commit adds a `devel` entry to the DSL, allowing formulae to
specify an unstable branch.

`devel` takes a block, which should contain standard `url` and `md5`
fields (and `version`, if necessary). This must come after the standard
DSL fields.

This commit also migrates over all formulae currently using `devel` to
the new syntax, as well as formulae which used `head` for non-VCS urls.

The new syntax is also available for `stable` and `bottle`. `stable` is
an option alongside the old syntax. `bottle` replaces the old syntax.

Note that the @stable ivar in Formula has been renamed to @standard,
and the @bottle ivar has been renamed to @bottle_url.

Closes Homebrew/homebrew#9735.

Signed-off-by: Misty De Meo <mistydemeo@gmail.com>

2 files changed, 8 insertions, 2 deletions

diff --git a/Library/Homebrew/cmd/audit.rb b/Library/Homebrew/cmd/audit.rb
index e980466da..5f4af55a2 100755
--- a/Library/Homebrew/cmd/audit.rb
+++ b/Library/Homebrew/cmd/audit.rb
@@ -290,7 +290,7 @@ module Homebrew extend self
     ff.each do |f|
       problems = []
 
-      if f.unstable and f.stable.nil?
+      if f.unstable and f.standard.nil?
         problems += [' * head-only formula']
       end
 
@@ -314,6 +314,12 @@ module Homebrew extend self
 
       problems += [' * invalid or missing version'] if f.version.to_s.empty?
 
+      problems << " * 'devel' block found before stable 'url'" if text =~ /devel.+(url '.+').+(url '.+')/m
+
+      problems << " * 'devel' block found before 'head'" if text =~ /devel.+(head '.+')/m
+
+      problems << " * Empty 'devel' block found" if text =~ /devel do\s+end/
+
       # Don't try remaining audits on text in __END__
       text_without_patch = (text.split("__END__")[0]).strip()
 
diff --git a/Library/Homebrew/cmd/install.rb b/Library/Homebrew/cmd/install.rb
index 735db6107..779482b7c 100644
--- a/Library/Homebrew/cmd/install.rb
+++ b/Library/Homebrew/cmd/install.rb
@@ -89,7 +89,7 @@ module Homebrew extend self
         next if f.installed? unless ARGV.force?
 
         # Building head-only without --HEAD is an error
-        if not ARGV.build_head? and f.stable.nil?
+        if not ARGV.build_head? and f.standard.nil?
           raise "This is a head-only formula; install with `brew install --HEAD #{f.name}`"
         end