Removed the option to specify an authentication database

MongoEngine does not currently support the ability to authenticate against
a different database than the one being used. A pull request to add this
feature has been submitted upstream, but not yet merged or released.

Until MongoEngine properly supports this functionality, it should be
replicated in the local app.

In the very short term, until the functionality is added locally, it will
be removed entirely to prevent PyMongo from throwing exceptions from
unknown arguments.
Merge branch 'remove_auth_db'

* remove_auth_db:
  Removed the option to specify an authentication database
Load the site-specific configs before the app or any blueprints are created

This way, the overwritten settings will all be available when the
blueprints create themselves.
Merge branch 'config_load_order'

* config_load_order:
  Load the site-specific configs before the app or any blueprints are created
Disable email field validation for users

'bev_1'-type users are failing to validate with this. Will create an
exception in the future.
Merge branch 'password_user_validation'

* password_user_validation:
  Disable email field validation for users
Added missing dbNew.html
Showing correct info in about tab
Doc: Updated administrative roles according to hackathon discussion
Few fixes to get admin UI regression
Merge branch 'dev/grant-revoke' of github.com:SlideAtlas/SlideAtlas-Server into dev/grant-revoke