Removed authId in favor of using ensembleUrl.  authId was redundant as
used to uniquely identify ensemble installation.
Method/event renaming:
hasAuth -> isAuthenticated
setAuth -> login
removeAuth -> logout
authSet -> loggedIn
authRemoved -> loggedOut
Refactoring to allow for multiple auth impls.
Removed auth util.  Auth is configured at app level and cached
(similar to app config).  Authentication handling and response caching
is now handled at a lower level and is more or less transparent to
views.