Bug 903 - NEWT: Support 'Continue Drag on Exit'; Consistent Mouse ENTER/EXIT

- Support 'Continue Drag on Exit'
  - Track dragging operation, allow exterior dragging
  - Hence track EXIT (see below)
  - Windows:
    - Capture mouse for exterior dragging
    - Only 'NewtWindows_trackPointerLeave' if 'entering'
    - Simplify touch: No 'inside' check - Not required.

- Consistent Mouse ENTER/EXIT
  - Track ENTER/EXIT and synthesize if required, drop duplicate
  - OSX benefits, since it never produced ENTER/EXIT events
  - AWT (or other TK) translated events beahve equal now.
  - Required for EXIT event after ending exterior dragging and final RELEASE

Tests: Passed unit tests 'junit.run.newt.event' on
  - GNU/Linux
  - Windows7
  - OSX 10.7

Tested exterior tracking manually w/ NEWT TestGearsES2NEWT and TestGearsES2NewtCanvasAWT:
  - GNU/Linux
  - Windows7 (mouse)
  - Windows8.1 (touch)
  - OSX 10.7