- Split out xorriso-tcltk from xorriso: The frontend is advertised
as proof-of-concept by upstream. Additionally, we can save a
dependency on Tcl/Tk on the main xorriso package.
- Cleanup using spec-cleaner:
+ use SPDX3 license string.
+ Package licence files as license, not doc (boo#1082318).

The split is essentially interesting as kiwi wants to use xorriso,
but pulling in Tk/Tcl is not appealing.