Current status
--------------
Given vectors ZCORN, COORD and ACTNUM as well as the Cartesian
dimensions these vectors implicitly refer to, the code is
currently capable of
* Identify unique points along each pillar
* Assign point numbers for each point specified in ZCORN
* Compute face topology, i.e., the corners that define the geometry
of the faces as well as the cells that are connected through the face.
* Identify and compute intesections that occur in the processing of
face topology.
What remains is
* Handle the face geometry of boundary faces. (simple)
* Compute point coordinates of the final point list.
* Put all pieces together in a tidy manner.
