Log message:
*: update gstreamer1 and plugins and related packages to 1.18.5

Based on the wip packages by nia and myself.

Log message:
*: recursive bump for libffi

Log message:
Add audio/gst-plugins1-gme

GStreamer is a library that allows the construction of graphs of
media-handling components, ranging from simple Ogg/Vorbis playback to
complex audio (mixing) and video (non-linear editing) processing.

Applications can take advantage of advances in codec and filter technology
transparently.  Developers can add new codecs and filters by writing a
simple plugin with a clean, generic interface.

GStreamer is released under the LGPL.

This package is part of the 'bad' plugins for GStreamer.  It provides the
game-music-emu plugin, which allows decoding audio for assorted video game
console hardware.