Rename addGesture and removeGesture to addEventListener and removeEventListener

This more accurately reflects that all event listeners can be added with these functions
Filter touches when scrolling

When native touch-action is supported, Chrome sends touchmoves with cancelable = false on the axis that is scrolling
html /deep/, not head /deep/
rough draft of trackX / trackY events
lowercase event names
Add default touch-action no matter how many listeners have been added before