Don't use audio.silent setting in SilenceableWaveFile

darcs-hash:20090905133700-867fb-59ba5f590aa0a875607984b7e326de5f3d3e09b2
Added direction argument to IMediaStream.initialize

Ignore-this: 36ba2b5ff1b5a39e5ef89acc7e27c6a3

darcs-hash:20090907083333-1e3d8-472d375f0e5c9c6122075794b6f3246a699354d4