Ensure FC ZoneManager is called

This patch ensures that the FC ZoneManager
is called during for all cases in Cinder
that does a volume attach/detach for FC
enabled drivers.
The problem was that we had code in the volume
manager that manually called the ZoneManager,
after initialize_connection and terminate_connection,
but other places in Cinder were not calling the
ZoneManager.
This patch creates 2 new decorators that can
be used for any driver's initialize_connection
and terminate_connection call.   The decorator
checks to make sure that the return value is for
a fibre_channel attachment and then calls the
ZoneManager's add_connection or delete_connection.
Change-Id: Ie3ae70785f500a140003ad3a8495e0ddc3516ea8
Closes-Bug: 1321798
Merge "Ensure FC ZoneManager is called"