controller_path is required by ActionView, so move it up to AbstractController and refactor AbstractController::Layouts.

Signed-off-by: NYehuda Katz <wycats@Yehuda-Katz.local>

AC::Head now doesn't have an unfulfilled Rendering dependency, and instead works just fine standalone (which means that ConditionalGet also doesn't have a Rendering dependency)

  * This initial implementation is a bit hackish, but it uses a normal middleware API
    so it's future-proof when we improve the internals.

	This is still not completely done and there might be pointers to things that don't exist yet.

This reverts commit 0cac68d3.

Refactored AbstractController to provide better hook points for overriding aspects of action dispatching

Got new base to pass controller/base_test.rb, implemented method_missing action semantics in compatibility mode, and fixed a few action_missing bugs.

This reverts commit a747ab5b.

Ported over the concept of public instance methods on controller child classes as callable action methods