Added support in openstack connector for additional disks, either empty or based on an image. Warning! Tested only for v2 Openstack API. Changes for v3 were not implemented

Change-Id: Ice2b39d05620ca3eb90704c07d0c5919e4474793
Signed-off-by: montesmoreno <pablo.montesmoreno@telefonica.com>
14 files changed