FMod - Full Audio Library

Though Abiathar will almost certainly not have a built-in sound editor, I wanted to have the appropriate classes in FleexCore just in case somebody else wants to do something like that. Today, I wrote all those classes and their IO methods in the GalaxyAudio class. Unlike GalaxyGraphics, it delegates the chunk loading and saving to the individual sound classes (PcSpeakerSound, AdlibSound, ImfSound) for ease of writing to individual files. I also did a lot of reading and research on the patching involved in adding songs, and it seems to not be terribly difficult.