0027899: Visualization, Ray Tracing - Provide ability to rebuild GLSL shaders on...

0027899: Visualization, Ray Tracing - Provide ability to rebuild GLSL shaders on the fly

For debugging and performance analysis it is reasonable to provide the ability to rebuild ray tracing shaders on the fly.
In this way, it will be possible to analyze the impact of different shaders modifications
without re-launching and re-configuring the scene.
This functionality can be used in the following way:
> vrenderparams -rebuild