Raytracer benchmark

This is a translation from Java/C++ of the raytracer located at http://www.ffconsultancy.com/languages/ray_tracer/
It mostly keeps the structure of the code of these other languages, but is still fairly Julian.
This code was discussed at https://groups.google.com/forum/#!topic/julia-users/UkeV1H9fct4
Speculation: this code's performance is bound by the garbage collector.