Until now we have used implicit timeout for message checking.
It is enough for the majority of the cases. But in cases of
overloaded deployment and more consuming actions (like manage
volume attachments) this timeout is enough for all the actions
except for messages so individual message timeout (adjustable
through horizon.conf) seems to be the best solution.
Change-Id: I6e43cdfa9fc02c1346b5a8228caacaf154e20ba3
Signed-off-by: Jan Jasek <jjasek@redhat.com>