Added a lot of code to enable shadows, and reflections.  There are some bugs in the ray tracing however, as I was unable to add a plane orthogonal to the direction the camera is pointing.  Also, there seem to be issues regarding the correct processing of the colors.  The cool feature is the fact that it has no problem rendering so many spheres with all the interactions at such a high speed.   This commit is the snapshot of the code as it looked when this youtube video was uploaded: https://www.youtube.com/watch?v=OU-01szfRns