DESCRIPTION:

When Eccet calls a script due to a mouse click/move or a
keypress, it will fill in the root.global.pointer struct.
This substructures describes the pointed-to voxel:
- x/y/z (int) the local coordinates of the voxel. x is -1
  if no voxel was pointed to. In this case the other values
  are undefined.
- name (string) the name of the voxelfield where the pointed-to
  voxel resides.
- norm/class/depth (int) the norm/class/depth field values of
  the voxel.