Note that the ruby-memcache bindings are required to use the memcache store.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3013 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/lib/action_controller/caching.rb

@@ -236,6 +236,7 @@ def after(controller)
     # * DRbStore: Keeps the fragments in the memory of a separate, shared DRb process. This works for all environments and only keeps one cache
     #   around for all processes, but requires that you run and manage a separate DRb process.
     # * MemCacheStore: Works like DRbStore, but uses Danga's MemCache instead.
+    #   Requires the ruby-memcache library:  gem install ruby-memcache.
     #
     # Configuration examples (MemoryStore is the default):
     #