Geos 5641 2.3.x

Pull request to fix 2.3.x branch for Issue [GEOS-5641](https://jira.codehaus.org/browse/GEOS-5641):
- merged already tested web/core/pom.xml changes from master
- updated German properties files (current translation status 100%)

Thanks to @oscarfonts and Stefan Engelhardt for supporting!