Feature detect deprecated web audio methods and mouse events

* Use non-deprecated node creation methods, falling back to deprecated (delay, gain, processor)
* Detect node methods like start/noteOn, stop/noteOff to use appropriate method, but non-deprecated where possible
* Use `shared` file's context in all files
* Set Oscillator's type via string rather than number
* Fix instances where setting a non number value to an AudioParam's value which would appropriate fail in Firefox
* Use appropriate `requestAnimationFrame` for x-browsers
* Use appropriate `getUserMedia` for x-browsers
*  Use x-browser wheel/mouse events for spatialized example