chatroom 6.x-2.0-beta3

bug fixes, feature polishing, next release should be an RC:

• cleaned up the UI a bit, new unified chat management interface
• #629400: make private chats controls easier to use
• #616868: provide an upgrade path from 6.x-1 to 6.x-2
• #636268: clean up theming of archived chats
• #636630: Missing t() in chatroom.theme.inc
• #629400: make private chats controls easier to use
• #636604: Typo in chatroom.install prevents uninstallation
• #636206: Editing a chat created whitin a chat room unlink it from the parent chat room
• fixed a bug with getting list of active chats
• make the latest message loading actually work

thanks to everyone who helped with bug reports, patches and ideas!