Thanks to Daniel KO Listas at the ODE mailing list
Don't build graphics demos when OpenGL or GLUT is not found
CMake will still build the non-graphical HelloWorld demo (output text to console)
Fix linker error: ThreadingDemo requires pthreads on UNIX systems
Thanks to reptor, see also http://bulletphysics.org/Bullet/phpBB3/posting.php?mode=reply&f=9&t=5748
Added Demos/ThreadingDemo showing how to use the cross-platform btThreadSupportInterface under Windows.
Added Demos/ParticlesOpenCL showing how to run the NVidia particle demo under OpenCL implementations by AMD, NVidia and MiniCL (CPU)