DPL GUI: support deferred GUI closure, if available

DPL GUI: support deferred GUI closure, if available

DPL GUI: support deferred GUI closure, if available

DPL GUI: support deferred GUI closure, if available

DPL GUI: support deferred GUI closure, if available

DPL GUI: support deferred GUI closure, if available

DPL GUI: support deferred GUI closure, if available

DPL GUI: support deferred GUI closure, if available

DPL GUI: support deferred GUI closure, if available

[EMCAL-551] Increase Cell ClassDef version

- Increase ClassDef version of cell to 2, as the type
  of the data word has changed from ushort array to
  char array
- Add method in LinkDef to convert the data words
  from the old format to the new format.