Fixed action/fragment caching using the filestore when a directory and a file wanted to to use the same name. Now there's a .cache prefix that sidesteps the conflict #1188 [imbcmdth@hotmail.com]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1260 5ecf4fe2-1ee6-0310-87b1-e25e094e27de