Add support for jpackage

[laeubi]

The jpackage tool will take as input a Java application and a Java run-time image, and produce a Java application image that includes all the necessary dependencies.

It would be cool to let Tycho support packaging an OSGi app into such a native package (msi, deb, ...) only drawback seems that it must run on the actual hardware for that but that might be okay for some use cases.