Fix fragment caching on Edge

Alright, here's a better patch. The last one was clouded by the tequila in my system and the in-laws yammering on about god knows what in the next room at the time of writing. Seriously.

Anywho, this is updated to check for edgeiness in a way that actually works - if [].respond_to?(:extract_options!) - , and also to fix the edge call to set_content_type! to pass in the controller as the first arg and not the action_cache_path.

First it fails by not having Hash#except or Hash#slice. So I add those in, then it fails with this: http://pastie.caboo.se/117570

Rails 1.2.5

Thanks for the hint on multi_rails. Here's a patch that refactors the test framework to use that, adds a test_with_125 rake task, and fixes the errors you mentioned.

Next up, if you're game (I'll open another ticket of course), is making cache_fu appropriately return a 304 status code when the client has the latest cached content and is inside the set TTL.