CMake and Compiling OpenSceneGraph (OSG) 3

[Canon]

I've been having problems with cmake and OpenSceneGraph since OS X Mountain Lion came out. Turns out it was in the CMakeLists.txt file that is included in OSG git.

I've included a link to an updated one below (I make no promises that this is safe to use or correct. It seems to work for my system though):

http://pastie.org/4642885

I had to add 10.8 checking on line 858. Hope this helps someone!