o This allows us to get rid of the ChannelRaw class
o Removed the sound index return value from several methods
o Removed all methods dealing with sound indices (i.e. stopChannel and pauseChannel)
svn-id: r11801
o Added SoundMixer::playInputStream and made some of the other play* methods use it
o Added ProcInputStream stub (not working yet) which one day may allow us to replace the premix code, and allow other fancy stuff
o Remove AudioInputStream::readBuffer default implementation (subclasses should always provide it for max. performance)
o Some minor cleanup
svn-id: r11754
