Refactor contrail-status to support systemd
Refactor contrail-status to support systemd

Also make some minor code cleanup about distribution and init system
determination.

Closes-Bug: #1640133
Change-Id: I9cc8abeca243a9cd7413395669c6f3fb40ed5365

rombie/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller