BUG-8893 patch port mysteriously deleted

BUG-8893 patch port mysteriously deleted

This happens sporadically when br-int exists prior to ODL
managing the OVS node. If the event notifying ElanOvsdbNodeListener
of the existence of the br-int bridge happens BEFORE the event
notifying about the OVS node the following occurs:

1. Netvirt gets event for br-int
2. Writes patch ports
3. Netvirt gets event for the ovs node
4. Creates br-int...which already exists and this over-writes the
   patch ports

Fix:
a) clean up code so that br-int is configured with a controller
   and patch ports only once we receive the notification for br-int
   in operational.
b) when receiving a notification for the OVSDB node in operational,
   check if br-int is in operational. If it is not, create it in
   config.
c) when receiving a notification for br-int in operational, check if it
   is also in config. If it is not, copy br-int fields from operational
   to config. The proceed to step (a).

Change-Id: I11739ccc847e65c4179ff1f73493159bd4effcd2
Signed-off-by: Josh <jhershbe@redhat.com>