p/fuel: armband formula: Refresh nova patches

p/fuel: armband formula: Refresh nova patches

Rework armband salt formula, focusing on nova libvirt driver patches:
- Switch from multiple individual patches to a single roll-up patch:
  * Patch is now applied for python directory instead of each file;
  * Expected hash is now 'False' (no hash checking for whole dir);
  * Added 'unless' condition to skip patching when already applied.
    Replaces old hash mechanism which was broken anyway when multiple
    patches are applied to the same file;
- nova: Switch guest video from VGA to virtio (replace our old
  standard VGA default patch with upstream backport);
- nova: Skip config/patch if 'python-nova' is not installed
  (e.g. for KVM nodes);
- nova: Support Qemu >= 2.10 (backport);
- libvirt: Re-enable Apparmor security driver on compute nodes;
- armband state is now fully re-entrant;

JIRA: ARMBAND-306
JIRA: ARMBAND-318
JIRA: ARMBAND-320
JIRA: ARMBAND-331

Change-Id: I48c09b10be030aa1ab4424b76876bf3dabd40fd2
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>