Log Message:
Update mame to 0.172.

It's with great pleasure that we announce the release of MAME 0.172.
This release includes several notable things above and beyond the
usual assortment of new systems, new features, and bug fixes.

Most importantly, this is the first release of MAME since the change
to a proper open-source licensing scheme as announced earlier this
month. From this release onward, MAME will be distributed under a
GPL-2.0+ license, with the bulk of code being covered under a
3-clause BSD license.

MAME now has an up-to-date set of documentation! You can find it
under the "Documentation" drop-down at the top of this site, or go
to http://docs.mamedev.org/ to check it out.

Due to the large number of configuration changes made in this
version, we strongly advise all users to delete their existing INI
configuration files and re-create them using the "-cc" option.

In case you are just overwriting previous release files note that
you better remove plugin folder first

For those of you running MAME on authentic CRT monitors, MAME now
incorporates a number of scaling-related features from GroovyMAME,
thanks to its author being brought on board the team, which should
help reduce user fragmentation. Please note: If you have issues
with MAME 0.172's graphics output, please ensure that "unevenstretch"
is set to 1 in your MAME configuration.

MAME 0.172 will also introduce a new high-score saving system using
Lua scripting. The feature is still experimental, but it's something
to keep an eye on for interesting future developments!

This version additionally marks the creation of a cross-platform
data-driven shader system via the BGFX renderer, which allows you
to apply shader effects per-screen, and more.