#3 Add unit tests to prevent regressions

[Eric Friedman]

With several developers working on this project, it
seems like it would be a good idea to add unit tests
that can be run prior to "cvs commit" in order to
verify that nothing has been broken. The JUnit
library makes this very easy to do -- see
http://www.junit.org/ -- see also the junit integration
with Ant (http://trove4j.sourceforge.net/ has examples
of this).