repaired Javadoc

I was generating Javadoc like `mvn clean javadoc:aggregate` and there were warnings regarding missing things. Generation of Javadocs are now totally without issues.

Anyway I would like to add GraphViz into it like it is done with ShrinkWrap API, that would be super cool

https://docs.jboss.org/shrinkwrap/1.0.0-cr-3/