Fix ceilometer-acompute rejoin problems

The problem was in the screenrc file generated, where the
following command appeared:

sg libvirtd "ceilometer-agent-compute
                 --config-file /etc/ceilometer/ceilometer.conf"^M"

The final "^M" was not then parsed.

Change-Id: Ie6c5b1c9e3d196a3a9c343c2afb46435711c10f5
Closes-bug: #1311666
Only use heat image where support

Glance will reject images that it doesn't understand, and only certain drivers can
use qcow2 images.  This means for systems without qcow2 support, devstack
will fail to run until this change is merged.

Change-Id: Ic92815f3d32880e987456c0428953dddaa81c94c
Closes-Bug:1313755 adding code to remove heat conf files

Change-Id: Iefe1a34b09958d21d2516fdce0937e00e32afcb5
Merge "Fix ceilometer-acompute rejoin problems"
Merge "Closes-Bug:1313755 adding code to remove heat conf files"