Added new document and document list attributes to displayed fields, added callback function (before insert) for setting creator and admin to current user creating a new document (list) and "created" timestamp. Timestamp setting is not working so far
Added new document and document list attributes to models and mappers for avoiding simultaneous editing of documents and document lists. The mechanism itself is not implemented yet.
Callback to update/set creator, admin and created fields on inserts
Merge branch 'crud' into master

Conflicts:
	application/libraries/crud_service.php
(Additions from both branches merged)