Macbook HiDPI support: reshuffled code to make it compile for 10.6 and work
in 10.7 and later. OS X Gurus might check though :)



git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@53663 954f8c5b-7b00-dc11-b283-0030488c597c