Fix func job hook script permission problems

- The hook script is the wrong place to unstack since
  it needs to run as the stack user with sudo privileges and those
  permissions are removed as part of the devstack-vm-gate.sh script.

- The functional job gate hook script needs to use sudo to
  install the test-only rootwrap filter.

Change-Id: Ib2e5ec016a5a414dd9675328650efb2b39b0e3fe
Related-Bug: #1360658
Do not use auto_schedule_routers to add router to agent

auto_schedule_routers makes a number of DB calls that are
unnecessary as they are already made during the validation
phase of add_router_to_l3_agent. Once the validation is
done, the only business left is to create the binding: this
is what this patch does.

Partial-bug: #1356121

Change-Id: Ia9be998c2b94416bc46ef78415099f0099b08c2a
Merge "Do not use auto_schedule_routers to add router to agent"
Merge "Fix func job hook script permission problems"