DESCRIPTION:

Find the smallest cube that contains voxels matching a given
condition.
Parameters can be any combination of
- c [classset] which will match for the given classes,
- g from to which will match the given grey range and
- d from to which will match the given depth range.
Giving more than one condition will yield the logic and of
the conditions. Giving the same condition type twice is not
allowed and will give undefined results.
The command returns a struct containing the elements
xmin/xmax,ymin/ymax and zmin/zmax