Issue #967164 by Berdir: Fixed privatemsg_roles tries to send message to uid 0 for authenticated user role.

#850022 by Berdir | BenK: Improved autocomplete for different recipient types and name conflicts between them.

#850996 by Berdir: Disabled tests which use batch execution because they do not work on all test slaves

#555016 by Berdir | neriweaver, trupal218, BenK, nbz, archard, nilsja, kriskd, Liliplanet, yaz085, litwol, Feet, jaron: Added recipient types, allowing to send messages to roles and other recipient groups.