Refactor TrashCanDao and TrashCanBackupDao to the proper package.
Add a new method to return trash items older than a specific time.
Remove unused imports.
Add cleaning up the ACL table for purging the trash can.
Expose the method to purge a list of trashed items.
Add a method to the manager for getting a list of trashed items before the specified time.
Rename method purge() to purgeTrash().
Add trash worker that purges trash older than a month.
Add sorting to avoid deadlocks.
Replace exception with logging.
Merge remote-tracking branch 'upstream/develop' into quickfix

Conflicts:
	services/workers/src/main/resources/main-scheduler-spb.xml
Merge pull request #665 from eric-wu/quickfix

Add a trash worker that purges trash older than a month