1. Moved ContrailVRouterApi and thrift client code to
   vnsw/contrail-vrouter-api.
2. Add tests for ContrailVRouterApi

Change-Id: I2561c5d08a8b2c23fcc7ab4125529165087284e7
Merge "1. Moved ContrailVRouterApi and thrift client code to    vnsw/contrail-vrouter-api. 2. Add tests for ContrailVRouterApi"