Input: Rename methods

onMosueButtonSixDown -> onMouseButtonFourDown
onMosueButtonSixUp -> onMouseButtonFourUp

onMosueButtonSevenDown -> onMouseButtonFiveDown
onMosueButtonSevenUp -> onMouseButtonFiveUp
nom::JSON::Value: Add support for arrays of ints
Add some documentation notes for onMouseWheel
Rudimentary support for joystick add/remove event
Rudimentary support for touch events

* Commented out; incomplete -- need to write virtual event handler
methods