NEWT/MouseEvent: Refine MultiTouch Event Spec regarding associated 'action' pointer Index; Add PointerType[PointerClass]; Add 'wheelScale' Attribute;

- Refine MultiTouch Event Spec regarding associated 'action' pointer Index
  In case an instance represents multi-touch events, i.e. {@link #getPointerCount()} is > 1,
  the first data element represents the pointer which triggered the action if individual to one pointer.
  For example {@link #getX(int) e.getX(0)} at {@link #EVENT_MOUSE_PRESSED} returns the data of the pressed pointer, etc.

- Add PointerType[PointerClass]
  This allows applications to identify the type and it's class [On-/Offscreen]
  helping to interpret semantics, e.g. wheel-rotate and new wheel-scale

- Add 'wheelScale' Attribute
  Returns the scale used to determine the {@link #getWheelRotation() wheel rotation},
  which semantics depends on the {@link #getPointerType() pointer type's} {@link PointerClass}.
  See API doc for details ..

TODO: NEWT/Android changes adopting these changes.
Android/NEWT MouseEvent: Fix Delivery of MultiTouch PRESSED/RELEASE; Fix Detection/Processing of 2-Finger-Scroll Gesture ; GearsES2: Add NEWT based 'zoom' gesture detection.

- Fix Delivery of MultiTouch PRESSED/RELEASE
  Adopting MouseEvent changes of commit 18cb57246372eda72c25a5cd9a69a873bdf09489

- Fix Detection/Processing of 2-Finger-Scroll Gesture

  Dropping utilization of Android's GestureDetector and implementing our own,
  which turns out to simplify keeping track of states.

  Our gesture detection works well w/ user NEWT based gesture detection (-> See GearsES2 zoom and rotate),
  using following criteria related to Android parameter:
     - ScaledDoubleTapSlop:
        - Max 2 finger distance

     - ScaledTouchSlop:
        - Min. movement w/ 2 pointer withing ScaledDoubleTapSlop starting 'scroll' mode
        - Max. change of finger distance in respect to initiating 2-finger distance (2x ScaledTouchSlop)
        - Max. distance growth in respect to initiating 2-finger distance.

- GearsES2: Add NEWT based 'zoom' gesture detection.