Watcher notification listener is associated with an executor which integrates the listener with a specific I/O handling framework. blocking executor should be the default one.
Watcher notification listener is associated with an executor which integrates
the listener with a specific I/O handling framework. blocking executor should be
the default one.

Change-Id: I10431fefa5f9d4dff3f8482a38c534f1263e67e8

stackforge/watcher,openstack/watcher,stackforge/watcher,openstack/watcher