Simplification of audio channel count defines & fix #23

[xross]

• Simplification of audio channel count defines
• Removal of AUDIO_INPUT/OUTPUT_CHANNELS defines
• AWE_INPUT/OUTPUT_CHANNELS defines now uses exclusively
• (if some channels are not destined to go to AWE this should be handled “higher up” in the app.
• app_usb_audio_awe now matches AWE channel count defines to UA channel count defines (avoids mem corruption issue - fixes #23)
• A bunch of automatic white-space removal

(Note, I fixed up all the example apps, not sure we're keeping them all though?)

[xross]

Looks good and glad to see you found the doc mention of AUDIO_INPUT_CHANNELS too. Only two questions:

• What to do about the other 3 apps - I think we both felt they don't belong in the main branch. Probs on a fork?
• xcommon support. Let's decide one way or another and stick to it.

Unless I missed something it looks like all four apps can be build configs of the one app.

I don't see an issue adding xcommon support if we have to (based on migrating lead customer). But adding a readme.txt about an xs1b lib doesn't mean we have to do it either (even if one will never exist).