Change to prefer Floating-IP over policy based forwarding.
fixes bug-2079
Adding test case for FIP preference over policy leaked route.
- Adding dest_vn to subnet drop route
- change for link_local route to have dest_vn same as vrf vn.
- corresponding change in test case.
- Taking care of review comments.
Changing compare to != as per review comment
Merge pull request #365 from Juniper/psethi_controller

Change to prefer Floating-IP over policy based forwarding.