Add unit test for ryu-agent

fixes bug #1118197

This patch adds unit test for ryu-agent.
Also, add the lacking test for the default configuration value.

Change-Id: I742b2a9dfc0706c0307365a3fe9496c3541fcf04
Modify dhcp agent for agent management extension

2nd part of blueprint quantum-scheduler

Remove openstack openstack listener on DHCP agent side.
Add DHCPagent notifier on quantum server side.

Change-Id: I196691650a99ba865bf06081a1fc4546f9fac7bd
Merge "Add unit test for ryu-agent"
Merge "Modify dhcp agent for agent management extension"