brew cleanup removes .DS_Store files

Probably slow, but we hate these fuckers.

Library/Homebrew/cmd/cleanup.rb

@@ -17,6 +17,7 @@ module Homebrew extend self
       clean_cache
       # seems like a good time to do some additional cleanup
       Homebrew.prune unless ARGV.dry_run?
+      rm_DS_Store
     else
       ARGV.formulae.each do |f|
         cleanup_formula f
@@ -65,4 +66,8 @@ module Homebrew extend self
     end
   end
 
+  def rm_DS_Store
+    system "find #{HOMEBREW_PREFIX} -name .DS_Store -delete"
+  end
+
 end