Introduced new scheme for setting up which version of OpenGL/OpenGL ES the OSG is compiled for.

To select standard OpenGL 1/2 build with full backwards and forwards comtability use:

  ./configure
  make

OR

  ./configure -DOPENGL_PROFILE=GL2

To select OpenGL 3 core profile build using GL3/gl3.h header:

  ./configure -DOPENGL_PROFILE=GL3

To select OpenGL Arb core profile build using GL/glcorearb.h header:

  ./configure -DOPENGL_PROFILE=GLCORE

To select OpenGL ES 1.1 profile use:

  ./configure -DOPENGL_PROFILE=GLES1

To select OpenGL ES 2 profile use:

  ./configure -DOPENGL_PROFILE=GLES2


Using OPENGL_PROFILE will select all the appropriate features required so no other settings in cmake will need to be adjusted.
The new configuration options are stored in the include/osg/OpenGL header that deprecates the old include/osg/GL header.
Added src/osg/OpenGL.in configuration file and include/osg/OpenGL header files