implemented a method for sorting values
implemented a column identifier
Modified Files:
src/java/de/fhworms/ztt/ox/campusdatarepository/StudentModel.java
src/java/de/fhworms/ztt/ox/examadministrationclient/StudentCatalogEditor.java
src_test/java/unit/de/fhworms/ztt/ox/campusdatarepository/StudentModelTest.java
