- fixed bios partition type setup:
  * upstream parted supports 'set partition flag state' whereas
    flag can't be a hex id as we need it when setting e.g a
    fat partition type. Thus we use the suse extension as fallback
    which allows to set: 'set partition type hexid'
- fixed base path setup in __populateCustomFiles
  * use of uninitialized value after handling that case