- added function createCustomHybridPersistent() which allows to
  provide the cmdline variable 'kiwi_cowfile=device:/path/to/cowfile'
  If kiwi get this information it uses the file as container for
  persistent writing for hybrid iso images. If this information is
  not present the standard case applies, which is kiwi tries to
  create a new partition device for persistent writing. In combination
  with the isofrom feature the kiwi_cowfile approach is useful
- fixed use of uninitialized value in KIWIMigrate
- remove autoyastClone function/feature from KIWIMigrate
  this feature did not work well and it's also not
  maintained by yast at the moment
- make sure KIWIMigrate writes latest version of the XML schema