GroupBasedPolicy/kilo-bug-squash

Pending bugs on master (and require backport)

Bug	Owner	master branch patch	stable/juno patch
ptg wrongly created with null subnet, cannot be deleted either	rkukura
Network Service Policy cannot be associated with multiple PTGs	magesh-gv	https://review.openstack.org/#/c/160710	https://review.openstack.org/#/c/161089/
rmd is not freeing address pools properly	magesh-gv	https://review.openstack.org/#/c/158057/
Changing L3P of a in-use L2P, does not reflect in change in subnet of PTG	rkukura	https://review.openstack.org/#/c/161065/
stale L2 policy persists even on its fail creation	rkukura
In-use Network-service-policy should not be allowed to get deleted	krishna1256
L3Policy create should have validity check for ip-pool	krishna-sunitha	https://review.openstack.org/158183	https://review.openstack.org/161081
L3Policy creation should error out if subnet-pr-len is greater than mask-length	snaiksat
Remove spaces in stackname in ServiceChainInstance create	magesh-gv	https://review.openstack.org/#/c/160747/	https://review.openstack.org/#/c/161086/
GBP Servicechain driver should validate the Service Chain Node definition	magesh-gv	https://review.openstack.org/#/c/160743/

Merged bugs, awaiting backport to stable/juno

Bug	Owner	Patch-link
Service Chain instance deletion should not error if corresponding stack does not exist	magesh-gv	https://review.openstack.org/#/c/160753/
Used servicec-hain spec can deleted although used by Policy Action	magesh-gv	https://review.openstack.org/#/c/160757/
referred/in-use L3policy deletion does not fail	rkukura	https://review.openstack.org/160947
In-use L2Policy delete should fail, otherwise results orphan neutron objs	rkukura	https://review.openstack.org/160947
L3Policy check for subnet-prefix-length smaller than pool subnet	snaiksat	https://review.openstack.org/160902