Frontend: enhanced exception messages of state machine
Frontend: fixed Trace.Call() calls in ChatViewSyncManager

Trace.Call() can't be tricked to log parameters that are not part of the
method's signature. If extra information is needed then the logger needs to be
used instead.
Frontend-GNOME: fixed not showing newly added IRC servers in join bar

When a new server was added from the Server -> Add menu it would not appear in
the join bar without restarting Smuxi.
Merge branch 'stable'