Update to new zuul-gearman protocol.

* Use non-Jenkins terminology "manager" rather than "master".
* Use name+number as the identifier for both stopping builds and
  descriptions.
* Expect 'url' parameter instead of 'full_url'.

Change-Id: I1fe9851556618fc6d6deb8906e3f2ee41725c3ad
Reviewed-on: https://review.openstack.org/31726
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins
Wait for internal gearman server to settle.

If we're using the internal gearman server, wait for workers
to register their functions before proceeding with startup.

This is mostly to handle restarts where we may be immediately
ready to run jobs, but workers may not have registered functions
yet.  In that case, we would immediately start declaring jobs
LOST.  So give them a chance to show up first.

The gearman-plugin for jenkins currently tries to reconnect
every 3 seconds.  We could probably even lower that to 1 or 2.

Change-Id: I173b16ba78cecac91acec26b4f2d55f38610e5a2
Reviewed-on: https://review.openstack.org/31735
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins