update window size after constrainFrameRect is called
Merge pull request #401 from nselikoff/osx-fix-constrained-window-size

Update window size after constrainFrameRect is called
Querying window size after setWindowSize() to determine post-constraint size on Mac
Adding missing libpng16 for Cairo Mac, and updating samples to match
Merge remote-tracking branch 'upstream/dev' into dev-scons