Any relative paths that the game tries to access in libretro builds will
now be relative to whatever is the current working directory in the Ruby
sandbox, which will also now be initialized to the game directory during
initialization. Before, all of the bindings that took paths were
hardcoded to prepend the path with the game directory.
This allows more flexibility when loading games in libretro builds,
since we can now load games either from a directory or from a ZIP or 7Z
archive. Also, the path cache is now active for all filesystem calls
made from inside Ruby.