See RHEL-1147 for details. Changes made to hostid creation should be reflected in blivet as well.

In short:

• hostid should now be derived from hostnqn by taking its UUID part
• existing hostnqn and hostid files should not be overwritten
• care must be taken on systems with no DMI records where random UUID is generated (TBD)
• the code should be ported to use libblockdev directly