Manage images according to openstack version

The patch implements logic to manage image files
according to openstack version. Instead of using m5sum
hash file is used.
Moreover br-baremetal bridge definition has been added
in order to get rid of its definition on cluster level

Change-Id: I7f7cd62d8c209ab75cdadf50e0b49cf7ae1a6dac
Related-PROD: PROD-24887
1 file changed