Merge gulafaran's and vodik's fork back with master.

[vodik]

Merge back @gulafaran's and @vodik's changes.

• Support for enumerating and controlling input and output devices and applications.
• Expose balance.
• Add is-muted command.
• Probably something else I'm forgetting.

Not sure if you want the whole 50+ commits as it, I can squash some commits if you prefer.

[vodik]

Clean reimpementation in #3