audio: Move code around and indentation (no actual code change).
 - Move functions to the top of the target file.
 - Create detect_adhd_head function.
 - Indent last part of target
croutonversion: Add -v to print crouton version only.
audio: Only rebuild when necessary
 - When crouton is updated (or always if version is git).
 - On Chromium OS releases updates.
 - Do not rebuild if ADHD git heads match.