Bug 7234 : Placeholder for BGP minor fixes

Bug 7234 : Placeholder for BGP minor fixes

Issue 1:
Modified BGP-Util MD-SAL read, not to supress the exception.
As this exception is used for BGP configuration retry mechanism.

Issue 2:
BGP stale path timer will be shown as default.

Issue 3:
BGP replay mechanism: Publishes internal VRF's & prefixes before
neighborship configuration.
6windQuagga EOR(End of Rib) marker: EOR Marker sent immediately after the
neighborship establishment.
So in case of BGP-restart scenario, 6windQuagga sends EOR immediately
after the session establishment,
in this scenario, the prefixes which are published earlier (before
restart) will be purged till CSC
replays them. Due to this there will be impact in datapath between
local-VM's to external DC-Gwy.

Change-Id: I6fababd4f8b5f8a96bc2f1e72fefdaf089f75d50
Signed-off-by: Vyshakh Krishnan CH <vyshakh.krishnan.c.h@ericsson.com>