Added Aether biome music

Small mod overhaul:
- (Nearly) all audio files have been re-encoded from original quality files with the latest Vorbis encoder with aoTuV and Lancer patches, resulting in better audio quality at a lower bitrate;
- Tweaked song loops, reducing audio downtime and mod size;
- "Doria" reduced to a 8 second loop due to the context of it playing on a world generation screen;
- Removed some nasty compression artifacts from a few songs;
- Pumpkin Moon's background music replaced to fit better with Frost Moon's music.

Altogether, the mod now weighs about ~40-50 MB less and should sound better. Enjoy!