This package is a half-hearted attepmt at simplifying and 
cleaning up R.L.W.L's original "libelast" library. 

(The directory "../tese-rluis-v2/" contains a more radical
rewrite attemp, that has been temporarily suspended.)

To make it easier to implement operations on models, I have replaced
opaque objects by explicit arrays and records,

I have retained the original design where the elements are stored in
arrays and referenced by numbers. To allow identification of elements
across topological operations, I have attached a name to every vertex
and every cell, and a letter label to each corner in a cell.

(This hack seems to work but is clumsy and inefficient; the right
solution is to use a tagged pointer data structure, as in the
quad-edge.)

I have also replaced materials and textures by names, which are bound 
only by the time the model is written to disk (and then only because
the file format requires it).

J.Stolfi, Jan/97