Added an omnipresent RailsInfoController with a properties action that delivers an HTML rendering of Rails::Info (but only when local_request? is true). Added a new default index.html which fetches this with Ajax.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2933 5ecf4fe2-1ee6-0310-87b1-e25e094e27de