Convert sfu_api plugin to Rails 3 routes

This appears to work, however I have only tested a handful of routes.

Test plan:

1. Test each route on a Rails 3 environment
2. Test each route on a Rails 2 environment to ensure back-compat

try to convert sfu_api plugin to rails3 routes

Doesn't actually work. I hate Rails.

change scope wrapper to let non-extension URLs work