test for adding crazy branches

as found by dansmith's clever hack, if devstack lands a crazy
branch name in stackrc, we'd break the devstack gate. While it's
doubtful anyone would do this, add a basic sanity check.

Change-Id: Ib3b1881ed4fd520a1828ed073a7c8353e6f0a839
remove docker from devstack

with I1c9bea2fdeebc4199c4f7d8fca4580a6fb7fed5b nova removed
docker from it's driver tree.

We shouldn't have driver support inside of devstack that's not
part of upstream projects (this has been a line we've been
pretty clear on with Neutron drivers in the past).

Remove docker driver accordingly.

Change-Id: Ib91d415ea1616d99a5c5e7bc3b9015392fda5847
Additional attempts to flosh stdout/stderr

The logfile output is piped through awk to apply a timestamp
and filter out all of the xtrace commands in the xtrace output.

A while back we added fflush("") which is supposed to flush all
open output files and pipes. It appears that gawk in precise
is old enough that it may only flush stdout, so explicitly
flush the logfile handle.

Change-Id: If5198c2da2a3278eed8ae3d50c7ca5c15eac6d94
Only stop n-cpu in stop_nova_compute

Move screen_stop n-cpu from stop_nova_rest to stop_nova_compute.

Change-Id: I672673a55869d3f68e12c476924fc742e8260f39
Merge "Only stop n-cpu in stop_nova_compute"
Merge "remove docker from devstack"
Merge "Additional attempts to flosh stdout/stderr"
Merge "test for adding crazy branches"
Merge branch 'master' of https://github.com/openstack-dev/devstack