Reordered the configuiration file blocks to make it more understandable
From Pjotr Svetachov, "For me osgviewer.cpp and Renderer.cpp were not compiling (visual studio 2013 with profile GL2) because they were still using GLuintEXT. So I changed that, see the attached files.

I also noticed that the generated OpenGL header were not copied to the installation directory so my own application could not find it."