Fix for stage lock (#134) and clarify user user permissions (#88)

How user levels now work:
Player - can only act/use tools on stage
Maker - all Player permissions, plus can make stages, edit stages they have edit access for, lock and unlock their own stages, upload and edit media, and edit their own account details.
Unlimited Maker - same as Maker, but with unlimited upload size.
Admin - all Unlimited Maker permissions, plus they can create/edit players up to Admin level, edit the editable pages, edit any unlocked stage
Creator - all Admin permissions, plus they can edit any stage regardless of locks, and can create/edit players with Creator permission level