New patch implementation and DSL

This commit introduces a new patch implementation that supports
checksums and caching.

Patches are declared in blocks:

  patch do
    url ...
    sha1 ...
  end

A strip level of -p1 is assumed. It can be overridden using a symbol
argument:

  patch :p0 do
    url ...
    sha1 ...
  end

Patches can be declared in stable, devel, and head blocks. This form is
preferred over using conditionals.

  stable do
    # ...

    patch do
      url ...
      sha1 ...
    end
  end

Embedded (__END__) patches are declared like so:

  patch :DATA
  patch :p0, :DATA

Patches can also be embedded by passing a string. This makes it possible
to provide multiple embedded patches while making only some of them
conditional.

  patch :p0, "..."

1 files changed, 6 insertions, 0 deletions

diff --git a/Library/Homebrew/test/test_software_spec.rb b/Library/Homebrew/test/test_software_spec.rb
index c35294320..7c9fb8720 100644
--- a/Library/Homebrew/test/test_software_spec.rb
+++ b/Library/Homebrew/test/test_software_spec.rb
@@ -80,6 +80,12 @@ class SoftwareSpecTests < Test::Unit::TestCase
     @spec.depends_on('foo' => :optional)
     assert_equal 'blah', @spec.build.first.description
   end
+
+  def test_patch
+    @spec.patch :p1, :DATA
+    assert_equal 1, @spec.patches.length
+    assert_equal :p1, @spec.patches.first.strip
+  end
 end
 
 class HeadSoftwareSpecTests < Test::Unit::TestCase