call security_groups_member_updated in port_update

When a running VM is added to a security group, all existing VMs (ports)
in the security group should be notified/updated - otherwise they would
have incorrect rules, not knowing the new VM/port added.

The current behavior would only update the port of the added VM. This
patch forces an security_groups_member_updated() call for all the
security groups that have ports removed or added.

Change-Id: Ibdcd74f47043762386b62f3ec0fa1723060446ac
Closes-Bug: 1316618
(cherry picked from commit e97eea83ae162b9ce0f45f1ff334dbf70608fe3f)
Add missing ml2 plugin to migration 1fcfc149aca4

Migration 1fcfc149aca4_agents_unique_by_type_and_host
shouldbe applied to ml2 plugin as well.

Change-Id: I3f5a2fcfec49316fbe06d6221d003aeb2599bca7
Closes-Bug: #1350326
(cherry picked from commit 30f1a75e790a512ea8b2b4997a634a50070fef9f)
Merge "call security_groups_member_updated in port_update" into stable/icehouse
Merge "Add missing ml2 plugin to migration 1fcfc149aca4" into stable/icehouse