JBPAPP6-1393 Fix backup bridge deployment: deploy&start bridges on clusterManager.activate()

Worth noting that activate now "throws Exception" because our code throws exceptions
from constructors. One must never throw exceptions from inside a constructor,
as it an anti-pattern for leaking resources.

https://bugzilla.redhat.com/show_bug.cgi?id=900764
Merge pull request #967 from FranciscoBorges/Branch_2_2_EAP

JBPAPP6-1393 Fix backup bridge deployment: deploy&start bridges on clust...