Cooja can not be built with newer Java versions

[nfi]

The API used for configuration in Cooja (javax.xml.bind) was removed in Java 11 and is no longer available (see http://openjdk.java.net/jeps/320#Java-EE-modules for more information). We either need to bundle the API as a separate jar (jaxb-api) or change the Cooja configuration API to not depend on this API.

Bundle the API via a JAR file would be simplest but taking the opportunity to change to use a Cooja specific API would avoid this dependency, could simplify the configurations, and allow us to finally get rid of a lot of unchecked Java warnings. Changing the configuration API would however break backward compatibility with older Cooja plugins. If the latter would be ok, I can setup a PR with a proposal for a new configuration API in Cooja?

[pjonsson]

Commit 848235a fixes the mentioned issue and Cooja builds with Java 11 now so I think this ticket can be closed.

[nfi]

Correct. Thanks!