Support github tagged download versions

eg. http://github.com/lloyd/yajl/tarball/1.0.5

Library/Homebrew/pathname+yeast.rb

@@ -87,6 +87,11 @@ class Pathname
   end
 
   def version
+    # github tarballs are special
+    # we only support numbered tagged downloads
+    %r[github.com/.*/tarball/((\d\.)+\d)$].match to_s
+    return $1 if $1
+    
     # eg. boost_1_39_0
     /((\d+_)+\d+)$/.match stem
     return $1.gsub('_', '.') if $1

Library/Homebrew/unittest.rb

@@ -151,6 +151,11 @@ class BeerTasting <Test::Unit::TestCase
     assert_equal '1.21', r.version
   end
 
+  def test_version_github
+    r=MockFormula.new "http://github.com/lloyd/yajl/tarball/1.0.5"
+    assert_equal '1.0.5', r.version
+  end
+
   def test_yet_another_version
     r=MockFormula.new "http://example.com/mad-0.15.1b.tar.gz"
     assert_equal '0.15.1b', r.version