Rename quantum repos to neutron

Only the repos are renamed.  This will coincide with the repo rename
operation on July 6.

See https://wiki.openstack.org/wiki/Network/neutron-renaming

Change-Id: I99fe1f80ffc7a54b958b709495b90f8d94d41376
Update OpenVZ driver image

11.10 simply does not exist, so this simply does not work. However,
devstack-gate tries to pre-cache all images referenced, so even
though we're not doing anything with this, it's breaking devstack-gate.

Change-Id: I64b03ed387f5205a885427498e8cf8c2a5b32b91
stable devstack should default to stable/grizzly

the default git review location was master, not stable/grizzly,
which makes no fun in doing backport patches.

Change-Id: I731c73724274e1f86daded7c0706409807cd5b12