x264 2197

Upgrade x264 to version 2197, the 2012-06-09 stable tarball.
Add a caveat advising the user to recompile brews that use x264.
Add a conditional when building head that sets `GIT_DIR` and runs
`version.sh` so that folks can easily see the current version.

Because version 2197 was inadvertently used a couple of commits
ago, some folks may have a tarball with this name in their cache
that will fail sha1 check.  Hopefully they will know enough to
delete the version in their cache and attempt the install again.
Compiles well using clang and llvm from XCode-4.3.2 on Lion.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/x264.rb

@@ -2,9 +2,9 @@ require 'formula'
 
 class X264 < Formula
   homepage 'http://www.videolan.org/developers/x264.html'
-  url 'http://download.videolan.org/pub/videolan/x264/snapshots/x264-snapshot-20120425-2245-stable.tar.bz2'
-  sha1 '969e015e5df24091b5e62873808e6529a7f2fb7f'
-  version 'r2189' # use version.sh to find this with brew install -i --HEAD x264
+  url 'http://download.videolan.org/pub/videolan/x264/snapshots/x264-snapshot-20120609-2245-stable.tar.bz2'
+  sha1 '9abf3129cf4ebdf4409164a9334f52aad935bdd2'
+  version 'r2197' # brew install -v --HEAD x264 will display the version.
 
   head 'http://git.videolan.org/git/x264.git', :branch => 'stable'
 
@@ -15,6 +15,10 @@ class X264 < Formula
   end
 
   def install
+    if ARGV.build_head?
+      ENV['GIT_DIR'] = cached_download/'.git'
+      system './version.sh'
+    end
     args = ["--prefix=#{prefix}", "--enable-shared"]
     args << "--bit-depth=10" if ARGV.include?('--10-bit')
 
@@ -29,4 +33,12 @@ class X264 < Formula
 
     system "make install"
   end
+
+  def caveats; <<-EOS.undent
+    Because x264 installs its library with a version number that changes,
+    any of these that you have installed should be reinstalled each time you
+    upgrade x264.
+       avidemux, ffmbc, ffmpeg, gst-plugins-ugly
+    EOS
+  end
 end