- update to 0.27.1
- fix the SDL build by fixing an incorrect patch.
- add missing build dependencies for SDL build
- flavourise in lieu of the removed stonesoup-sdl port
- mention flavours in pkg-descr
- rework patches to be compatible with new version
- add desktop entry for the SDL version
- enable concurrent installation of the two flavours
- remove the somewhat pointless EXAMPLES option which used
to just install one file into an additional location
PR: 259509