Geolith ported to libretro

We have the pleasure of announcing a great new emulator core, the Neo Geo
emulator Geolith. The upstream author of the Jolly Good Emulation project broke
out this core and ported it to libretro to make it available to as many users
as possible, and we're happy to welcome it into the fold.

Historically, Neo Geo emulation has fallen under the general 'arcade' umbrella
and has been handled very capably by FBNeo and MAME. However, arcade emulation
is significantly more complex than the console emulation that most users are
accustomed to (with ever-changing ROMsets consisting of many tiny files in
strangely named zip files to keep up with; specific jargon, like "parent ROMs"
and "non-merged sets"; and additional files that sometimes go alongside the
game ROMs and sometimes need to live in other places), and this added
complexity can be enough of a hurdle that some users struggle to have a good
experience with all of the bells and whistles they have come to expect.

This is exactly where Geolith stands out, as it uses static,
one-file-equals-one-game ROMsets in the .NEO format developed for the NeoSD,
and also used by the FPGA-based MiSTer Neo Geo core. So, if you have dumped
your games to be compatible with those devices, they should benefit from full
libretro database support and all that entails. That is, simple, one-click
scan-and-import into a properly named playlist (with properly named games;
you'll see 'Art of Fighting' instead of 'aof' without any esoteric fiddling
with DATs and so forth), with appropriate icons and boxart/thumbnails
automatically applied. This separate, dedicated database and playlist makes it
easier to find the games you want to play with less time devoted to setup.

Users who cleared the complexity hurdle of arcade emulation have grown
accustomed to FBNeo's tight and feature-filled libretro integration, which sets
a very high bar for Neo Geo emulation by providing for a fast, accurate and
bug-free experience with full support for some of RetroArch's more finicky but
high-value features, such as rollback-based netplay and
runahead/preemptive-frames. Geolith's author has put in the effort to provide a
comparable, robust experience, so users don't have to compromise when using
this new core.

We're still polishing up a few rough edges on the database (about 20% of games
don't pull thumbnails yet), and we're working to get the core available on
Steam as DLC at the time of this writing, but we hope you enjoy it.