Higan - a quick&dirty workaround

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: Updating builder.sh script

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.
Merge pull request #3886 from AndersonTorres/higan

Higan - a quick&dirty workaround