Fixes issue 3326: TopicBar shouldn't reset the topic if someone else changes it whilst it is being edited.

Change-Id: I5ca1535dc9edbc9eac237f83c69efc3b910c3013
Reviewed-on: http://gerrit.dmdirc.com/248
Tested-by: Gregory Holmes <greboid@dmdirc.com>
Reviewed-by: Chris Smith <chris@dmdirc.com>
Tested-by: Chris Smith <chris@dmdirc.com>

Change-Id: I9ce55688263e8e016046296bd366a4d6936a41f1
Reviewed-on: http://gerrit.dmdirc.com/234
Reviewed-by: Gregory Holmes <greboid@dmdirc.com>
Tested-by: Gregory Holmes <greboid@dmdirc.com>

Change-Id: Ie8fe55536d320ab50472d8090b63c701cc4b12ba
Reviewed-on: http://gerrit.dmdirc.com/230
Reviewed-by: Shane Mc Cormack <shane@dmdirc.com>
Tested-by: Shane Mc Cormack <shane@dmdirc.com>