Log Message:
libretro-beetle-saturn: add version 20180620.

Libretro is a simple but powerful development interface that allows for the
easy creation of emulators, games and multimedia applications that can plug
straight into any libretro-compatible frontend. This development interface is
open to others so that they can run these pluggable emulator and game cores
also in their own programs or devices.

Beetle/Mednafen Saturn is a Sega Saturn video game system emulator that can
be used as a libretro core.

Mednafen can load CD-ROM games from a ripped/dumped copy of the disc, such
as CUE+BIN. Additionally, there is support for CloneCD "CCD" rips, and \ 
cdrdao
"TOC" files. A CUE file is required.