eventsjs flags for different events(mouse/touch/pointer) return wrong data on IE11

[dhara-02]

These are the flags used by eventjs to detect mouse, touch, pointer events respectively
eventjs.isMouse
eventjs.isTouch
eventjs.isMSPointer

These flags are set wrong when we work on IE11 : It always sets eventjs.isMouse = true, even if event type is pointerEvent and when we have touched the target element , it should be eventjs.isMSPointer = true

[kangax]

/cc @bterlson @dstorey @jonathansampson

[dstorey]

Probably should remove the MS part of isPointer as other browsers are supporting (unprefixed) Pointer Events. IE11 and Edge are unprefixed too.