alsa sound driver for EV3 speaker
add sound input device to support system beep
Merge pull request #7 from dlech/alsa-sound

alsa sound driver for EV3 speaker - merging into next kernel. Dave, do you have some notes on how to make the tone generation work?

Side note, I've bought a Bluetooth speaker so that we can experiment with streaming audio from the brick. Not that it's going to be an awesome sound player, but it's a way to at least make the sounds less horrible!