Merge pull request #234 from csmith/master

Separate most swing logic from core model.
Tidy up away states in Connection.
Switch back to String for away message.
Commit tests as well...
Merge pull request #235 from greboid/tidying

Tidy up away states in Connection.
Camel case ServerInviteReceivedEvent.java
Rename file too.
Initialise the away message to empty.
Merge pull request #236 from greboid/tidying

Camel case ServerInviteReceivedEvent
Fix Away Messages.
Merge pull request #237 from greboid/awaymessages

Fix Away Messages.
Change to Connection in ExternalCommands.