Retouch footer emboss.
Fix pot rotation in Webkit.
Downsample cabinet impulse response to 16 bits/s since Firefox can't handle 32 bits/s.
Remove deprecated playbackState property check on input play / stop.

This exposes the underlying API implementation's exception mechanism so users should beware that they have to handle exceptions when they call start or stop two times in a row.
Remove mozAudioContext since Firefox already implements Web Audio API without moz prefix.
Refactor ConvModel and its subclasses, fixing arbitrary iRPath property assignment.

The property belongs to CabinetModel but was declared on its parent, the ConvModel.
Fix JSDoc on ReverbModel iRPath property, stating explicitly that it's an override.
Fix JSDoc on input and outputBuffer types in ConnectableModel.

Replace deprecated AudioGainNode with GainNode.
Update tartJS submodule for Web Audio API externs.
Shim AudioContext on window, instead of the pb namespace.
Shim getUserMedia.
Implement error handler for getUserMedia.
Implement deprecated playbackState for Input.

The exception handling stuff is boring for the developer.
Build 0.4.0.