Refactor audio to use new config var callback instead of menu API
Created originally on Bitbucket by dmilligan (David Milligan)
The audio stuff is quite a mess and needs more refactoring than this, but I don't really have time or desire (I never use in camera audio, so what's in it for me?). Also, I have no way of testing the audio-lapis stuff so I don't even know if screwed something up. Probably needs some basic testing by someone with this camera before merging.
Anything else besides this that needs to do stuff when config vars change (needs a CBR)?