primesense: Record oni file while grabbing data.

This way we obtain the original camera data while using something that
uses it, e.g. KinFu.
primesense: Switch from YUV to RGB24.

This makes simultaneously recorded .oni files work in programs that
can only work with RGB, e.g. kfusion.
marching_cubes: Use bit shifting instead of multiplication.

When the point is to set bits in a flag, using shifts
makes it more obvious what is happening.
marching_cubes: No need to use shared.

Why was it there in the first place?
kinfu: Make (at least nominal) difference between usual and mesh points
WIP: kinfu: Add colors to marching cubes mesh extraction