*Title: Trash

*Incentive:
Deleted objects are available for all users (without checking of rights).

*Documentation:
New table 'ezcontentobject_trash' was added to store main nodes of removed
content objects. Also added new class 'eZContentObjectTrashNode' to maintain
entries in new trash table. Appropriate rights checking for fetching list of
accessible trash entries implemented for currently logged in user for now.