app: Add quantum adapter

Based on the following patch:

From: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Subject: app: Add quantum adapter

Thanks to Kaneko for finding and fixing my bugs.

Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
ryu/app/simple_vlan: simple VLAN app for OVS

Based on the following patch:

Subject: ryu/app/simple_vlan: simple VLAN spp

This application provides VLAN separation with ovs tag function.
Something similar openstack quantum openvswitch vlan function.

Example to run:
ryu-manager ryu/app/simple_vlan.py \
            ryu/app/quantum_adapter.py \
            ryu/app/rest.py \
            ryu/app/rest_conf_switch.py \
            ryu/app/rest_tunnel.py \
            ryu/app/rest_quantum.py

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>