Refactoring of jaxws contextLogger

Hi,
please review my changes at the contextlogger module responsible for the jaxws implementation.
The biggest change regarding the logging logic is threadlocal cleanup. In the current version on the master branch the cleanup happens only after an exception has been occured. I think we should cleanup the threadlocal after every request regardless of exceptions. To implement it I've removed the 'final' modifier on the close method in AbstractTraceeHandler.class.class and overridden it.

All other changes are minor ones. I've added testcases to reach 100% line coverage. Please review the cases as well.

Best regards and thanks in advance,
Sven