Determine file extensions supported by Game_Music_Emu

[Damian Yerrick]

lsb_release -rd says:
Description: Ubuntu 16.04.2 LTS
Release: 16.04

apt show libgme-dev says:
Package: libgme-dev
Version: 0.6.0-3ubuntu0.16.04.1

I am developing a music player and want to list all types that my music player's Game_Music_Emu plug-in can play. I can iterate through types with gme_type_list(), but all I can retrieve about each gme_type_t through the C API are the name of the console it's associated with (gme_type_system()) and whether the type supports multiple movements (gme_type_multitrack()). I'd like to be able to look up the most common extension associated with a track. I can go from extension to type (gme_identify_extension()), and I expected there to be a function to go the other way, but there wasn't.

I've filed related issues on other forks of GME:

https://github.com/kode54/Game_Music_Emu/issues/7
https://bitbucket.org/mpyne/game-music-emu/issues/13/list-all-supported-extensions

One fork maintainer plans to fix it by adding a function with the following signature:

const char *gme_type_extension(gme_type_t);