OPUS encoding support

[opusboi]

http://opus-codec.org/

The Opus codec is impressive. retains the same quality of mp3 at half the bitrate (sometimes even more than half). And it's more efficient than vorbis as well. So file sizes can get even smaller for mods.

Would be a good addition to MO3 since one of its features is smaller module sizes.

[andrew-479]

Agreed, Opus support would be awesome. Conventional lossy formats are nowhere near its efficiency. But it's a rather complex codec to implement