CLOUDSTACK-5587, CLOUDSTACK-5589: Router version in 2.2.x routers is null. Added null check when comparing min version
CLOUDSTACK-5300: Catch vpn add error failure, removed failed user and return failure status
fix network ACL unit test
CLOUDSTACK-5518: Fixing non contiguous vlan test case
CLOUDSTACK-4780: Changes related to checking snapshot path
 on NFS server, also made marvin import paths specific