Releases for Privatemsg Views

Long awaited release.

Fixes:
#812692 by crea: Don't count duplicates when author is in recipient list
#861560 by crea: Added temporary workaround for mailbox pager not working
Fix for views_bulk_operations_form altering to reflect changes in VBO code
#921744 by jcnventura: Inbox messages not linking to correct URL
#1135276 by catch: Static caching for _privatemsg_views_count_new_msg()