Solving ancient Blender window sizing issue;

- Removed grid-snapping for area coordinates on scaling windows. 
  That caused the areas to shrink or expand, and eventually corrupt screen layouts.

- Added simple but efficient life resize for OSX. I need to know why this is so much
  code for Windows... I suggest Windows to just copy same method; dispatch the queue,
  and just let the event system draw.



git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@57018 954f8c5b-7b00-dc11-b283-0030488c597c