Investigate projects as Java 9 Modules

[DavidWhitlock]

I've had students who wanted to use the JAXB API for generating XML/JSON for their text file. This seems like a reasonable thing to do because JAXB is a standard Java API. In fact, I use it in the example code in a couple of places.

As part of the Java 9/10 migration work, I added --add-modules java.xml.bind to the javac command line in Maven.

However, that's insufficient for running the program. (When a student use JAXB this term, I had to add --add-modules to the java command line in the grading script.

I should investigate the proper way to have the student projects depend on JAXB.