Add automatic module names (fixes #245)

[triceo]

This PR adds proper automatic module names to every JAR in the project. They can be checked inside the JAR's META-INF/MANIFEST.MF. Some things to consider before merging:

• People will reference these names in their module descriptors. Therefore, they should be considered public API. Please review these names and make sure you are comfortable with them, before you make them permanent.
• These names should become the proper module names, if/when multi-release jar for jdk11+ missing #237 is worked on. The project can now be included in modular Java applications, but to achieve full modularity, the modules of this project should provide their own module descriptors.

Word of caution: on my Java 11, I still wasn't able to build the project cleanly. I have to -DskipTests, as plenty of tests fail with Java 11. (This PR has no effect on that, neither should it.) Also, for some reason, JaCoCo also throws a lot of exceptions, although I don't have that problem with my own projects using it.