Unit Tests: Add [manual] demo cases for SWT (TestGearsES2SWT, TestGearsES2NewtCanvasSWT); Add more AWT/NEWT layout scenarious.
NEWT/OSX: Fix 'locationOnScreen' usage and use proper client-area window screen position (Fixes resize -> position)

- Tested w/ NEWT GearsES2 and Java6 and Java7 on OSX
NewtCanvasAWT: Fix size determination, i.e. take newt-child's size into account if no preferred size is given.