This is a preliminary implementation of the tracing procedure to compute
one proper equilibrium, described in Yamamoto's 1993 IJGT article.

The tracing implementation needs redone to a predictor-corrector method,
using Newton's approach to finding the points at which the path is not
differentiable.

The included Makefile assumes that libgambit has been installed in a
standard place (e.g., /usr/local).
