xci: scripts: start-new-vm.sh: Use Docker to build OS images

xci: scripts: start-new-vm.sh: Use Docker to build OS images

Use a docker container to build the OS images so we can build images and
start new virtual machines on all supported operating systems. This way
all developers can now launch a virtual machine to quickly reproduce
Jenkins results which should assist with debugging problems.

Since the container runs with elevated privileges it's best to ensure
that we have exclusive access to devices. Finally, we remove the
build-dib-os.sh script which is now part of the container itself.

The build image process now becomes more stable since it runs on clean
evnironment all the time so the only external factor is the upstream
distribution repositories.

Change-Id: I6b443192419ee2546a23430f421b152766d16333
Signed-off-by: Markos Chandras <mchandras@suse.de>