Generic Missing Template Exception Message

Okay, with all my whining in the last thread, I thought I'd take some
time to fix a real problem. I'm not sure if anyone else has noticed,
but the Missing Template messages have become generic in edge rails
since view_paths were introduced, because they are relying on
ActionView::Base.full_template_path which used to return a static
filename, but now returns nothing if a template is not found.

I have submitted a fix and looking for feedback as to the formatting:

http://dev.rubyonrails.org/ticket/8683