Incorporated a workaround for an OpenGL normal array state leak on Mac OS X 10.9 with Nvidia graphics cards. See WWJ-450.

git-svn-id: http://worldwind31.arc.nasa.gov/svn/trunk/WorldWind@1847 822214bb-dcf7-4c8d-a767-17ae0fb20d88
Merge branch 'official' into worldwind-sdk