Adding skeleton for a new daemon: prc-manager

The name stands for 'physical router configuration manager'.
It listens to rabbit-mq updates from API server. When messages are received, it reads corresponding information from cassandra. It manages configuration for physical routers (MX only for now) using netconf utility.

Change-Id: I36ac5f8999f8f921f4ecec1bc87d4c7742ed88df
Merge "Adding skeleton for a new daemon: prc-manager"