#166 Rewrite all tests for easy wrapping

[Glen Lewis]

Re-write the existing tests so that the real
functionality is in a util-type class that could be
re-used easily in JUnit. Then refactor the DTnnn tests
so that they are calling these utility classes.

At least try a few of these and see how well it is
working. If it goes well, it may lead to the
GenericJavaTestMapper (and others) facilitating greater
code re-use and niftier features.