API and Regular authentication refactor
Regular authentication had SSO, and http basic auth. API had Oauth
and http basic. This basically merges them both into a single file,
since there was a lot of overlap between application_controller and
api base_controller. A major benefit this brings is the possiblity of
using Apache REMOTE_USER authentication through the API which was
not possible before.

Assert_response is the proper way instead of assert_equal