Remove old IInterRegionComms and references.  This hasn't been used since 2009 and was superseded by ISimulationService
Fixed offline IM
In the offline message table, store the sender.

This data is useful for preventing abuse (e.g., someone who sends too many messages), or for deleting message if their sender has been deleted.
Can delete the Offline Messages sent to/from a user.

This is useful if the user is deleted.
Merge branch 'justincc-master'