The nixpkgs-unstable channel's programs.sqlite was used to identify
packages producing exactly one binary, and these automatically added
to their package definitions wherever possible.
- Simplify some symlinking
- Don't remove the temporary run directory: umoria allows for dumping
character info, which would be in there and inaccessible after
saving the game otherwise. The system takes care of cleaning up
the temporary directory anyway.
- Allow passing arguments to the wrapped executable, allowing using
different save directories, passing game seeds, checking out
highscores, etc.
It was impossible to continue a saved character before, as the
`cleanup` function would remove the whole temporary RUNDIR, including
the actual save file.
umoria allows passing a custom save file location, which now points to
the already-used data directory ~/.umoria.
Fixes#178136
