Region administration REST API

As a user, I would like to use REST API to administer the region definitions and device membership.

Predicated on ONOS-2863

Implementation Notes:

• Create a RegionCodec
• Create a RegionWebResource to support the following:
  • GET /regions - lists all regions
  • GET /regions/id - list region details
  • POST /regions id name type [ nodes ] - adds new region
  • PUT /regions/id id name type [ nodes ] - update region
  • DELETE /regions/id - removes region
  • GET /regions/id/devices - lists all devices in a region
  • POST /regions/id/devices [ devices ] - adds devices to region
  • DELETE /regions/id/devices [ devices ] - removes devices from region