Enable Devise for Screen authentication
auth! fixup for frontend controllers

Allow auth! to work in cases where the controllers are namespaced but
the corresponding models are not (previously it was tailored for cases
where they were both namespaced under the same module).
Add a dummy screen authentication mechanism

This does not actually verify any credentials. It is just to test the
login concept and test authorization code.
Correct authorization rules for Screen accessors.
Allow CanCan to use the current logged-in scren for auth

Pages must be designated as Screen API pages for this to work.

The Ability returned by current_ability can now either be based on a
screen or on a user, depending on the context.
Implement some authorization checks on the frontend.

This may not be complete.
Merge branch 'master' into screen-auth

Conflicts:
	config/routes.rb
Merge branch 'master' into screen-auth
Merge branch 'master' into screen-auth
Dump devise for screens in favor of a simple token system

Uses "permanent" cookies and verifies them at each request. Of course,
the frontend to authenticate a screen is not done yet.
Merge branch 'master' into screen-auth
Add a mechanism for setting up secure screens

Some screens#edit work will be required before the whole process works
without console access, and the new frontend screen log in view needs
some javascript for polling. Nonetheless it should be a good proof of
concept -- ou can actually authenticate a screen pretty easily as long
as it accepts and stores cookies.

Also all screen auth now resides in the frontend screens controller,
rather than a separate controller, and works along side the legacy
(MAC address) screen support.
Merge branch 'master' into screen-auth
Periodically auto-refresh screen sign-up page

This is a quick and easy way to automatically log in the screen once
an administrator has configured the auth code in the panel.
Fix some screen permissions and tests in frontend
Another screen test fix
Indentation fixes
Auth check in frontend screen setup (+test)

Also prefer 403s over redirects for screen API auth failures.
Merge branch 'master' into screen-auth
Merge branch 'master' into screen-auth

Conflicts:
	app/controllers/frontend/contents_controller.rb