Refine Int -> Enum conversion (commit 40863632d1428de015099b5967e5136425e99f25), throw IllegalArgumentException if ordinal is out-of-range. Add API doc.

- FFMPEGNatives
- MouseEvent.PointerType
NEWT Multiple-Pointer API: Use PointerType[] instead of ordinal int[], implementer can use PointerType.valuesOf(int[] ordinals) to convert. Enhanced API doc. Methods 'final'
Regression of commit a90bf31f8747dd38c61d518f8af4d4d4a64a8e90: 'consume<Type>Event(<Type>Event ..)' must be protected and non-final

Overriding by impl. class allowed.