Disable secgroup extension when Noop Firewall driver is used

When Noop Firewall driver is used, Quantum security group actually does
nothing in OVS and Linux Bridge plugin. It would be better to disable
security group extension for such case to avoid confusion.
By this we can determine whether quantum security group is enabled
by checking the extension list.
This commit changes OVS/LB/NEC/Ryu plugins with agent firewall_driver
based security group implementation.

Fixes bug #1124117

Change-Id: I2182289c1e27987b686f1adb7d6e2ad4e154caa2
Merge "Disable secgroup extension when Noop Firewall driver is used"