Merge pull request #57 from haripk/R1.06

Neutron to VNC update for nameservers and host routes
Support neutron subnet-update
Merge pull request #58 from enovance/subnet_update

Subnet update
Append security group entries without flushing existing entries
Merge pull request #61 from Juniper/praneet_sg

Append security group entries without flushing existing entries