add support for Retrolink N64 controller on Firefox and WebKit
Merge branch 'n64' of https://github.com/cvan/HTML5-JavaScript-Gamepad-Controller-Library into cvan-n64

Conflicts:
	doc/classes/Gamepad.html
	doc/data.json
	doc/files/gamepad.js.html
	gamepad.js
	gamepad.min.js
Merge branch 'master' into cvan-n64

Conflicts:
	doc/classes/Gamepad.html
	doc/data.json
	gamepad.min.js
Merge branch 'cvan-n64'