[Bf-committers] Cleanup of video/audio "rendering"

[Bastien Montagne]

Hi devs,

Here is a patch that attempts to fix how to "render" audio-only in 
Blender (see also bug #36819 http://goo.gl/TxVAFr ).

http://www.pasteall.org/46557/diff

Current situation: we can output audio-only files either with the 
mixdown operator (Audio panel in Scene context), or by using an 
audio-only format in FFMPEG's Encoding options, and render (yes! 
_render_ ) the scene as usual, yet getting only an audio file... 
Needless to say what to think about that latest solution!

Proposed fix:
*Remove audio-only format from FFMPEG Encoding options.
*Move mixdown button next to the Render/Animation ones (and rename it 
"Audio").

Rational behind the second change is that people often "forget" the 
Scene context, and do not find (easily) how to export audio! I know 
Blender is in no way an audio editor, but exporting audio can still be 
very useful in many situations, no need to hide it into an obscure, 
closed by default panel. ;)

Anyway, thoughts from UI team and all are of course welcomed! :)

Bastien