humaninput.js:  Added a new setting: 'moveThreshold' that controls when a 'hold' event will be cancelled for mouse/pointer/touch events.  Basically, if the pointer moves farther than 'self.settings.moveThreshold' pixels the 'hold' event will be cancelled.
humaninput.js:  Added a new setting: 'moveThreshold' that controls when a 'hold' event will be cancelled for mouse/pointer/touch events.  Basically, if the pointer moves farther than 'self.settings.moveThreshold' pixels the 'hold' event will be cancelled.

liftoff/HumanInput,liftoff/HumanInput