added a Dune 2000 SOUND.RS parser

again @pchote via IRC
implement the fact chunk for WAVE files
replaced Dune 2000 AUD with original WAV

removed *.aud hard-coding everywhere
Add Stream.ReadASCIIZ for d2k.
Fixup: Use ReadASCIIZ in D2kSoundResources.
Ignore unknown wav chunks instead of throwing.