Now we can parametrize Higan locally.
By default, guiToolkit = "gtk" and profile = "performance" (the accuracy
profile is seriously slow on my machine :) )
Closes #4340
Now builder.sh will install a higan-config.sh script
to write auxiliary stuff on $HOME/.config/higan directory.
That way, higan searches locally and runs cleanly.
Obviously it's a hack, but the only other way is to do a huge patch on
upstream sources; personally I think it is better to work that type of
thing directly on higan sources.
Higan uses a lot of hardcoded paths when it looks for runtime files
as shaders, icons and mainly BIOS files. So, we made a q&d wrapper
script: it copies all these files to $HOME/.config/higan in the 1st
invocation.
Higan is a cycle-accurate Nintendo multi-system emulator
It is a preliminary release for Nix - I need to investigate
some issues about install process and hardcoded paths...
