Tweak BgpPeerNotification log to display TCP endpoint if there's no Peer.

Add tests to exercise the code that sends a Notification when BgpPeer is
marked deleted or is being closed.
Add test for deferred peer close.
Avoid timer cancel deadlock
Merge pull request #631 from haripk/master

Avoid timer cancel deadlock, fix build error with timer UT
Fix build
Remove copyright
Add RoutepathReplicator test to verify instance route target update.
Merge pull request #632 from pedro-r-marques/pmaster

Fix build
Add another test where the target goes away and new one is added later.
Merge pull request #633 from Juniper/nsheth_instance_rtarget_update

Add RoutepathReplicator test to verify instance route target update.
Merge pull request #626 from Juniper/nsheth_notification_log

Tweak BgpPeerNotification log to display TCP endpoint if there's no Peer...
Merge remote-tracking branch 'upstream/master'