message: clusterizer: Add references
diff: #include <math.h>
  #include <string.h>
  +// This work is based on:
  +// Graham Wihlidal. Optimizing the Graphics Pipeline with Compute. 2016
  +// Matthaeus Chajdas. GeometryFX 1.2 - Cluster Culling. 2016
  +// Jack Ritter. An Efficient Bounding Sphere. 1990
  namespace meshopt
  {
  