Core/messages: Bugfix for channels with ":" in the name.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
(cherry picked from commit 4f1c650f1017655aaa4e025859940bc0183231f4)
Core/messages: Empty results from message parsing were breaking CUT. Now raise an error.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
Core/messages: Was broken for some message types.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
(cherry picked from commit a1424df660fc1da5a0fa0edb363ae5e21c1627e0)