editGrade/updateGrade/DB-queries

* editGrade af
(TestLine: http://localhost:8080/PDL/editGrade?testID=45&studentID=28)
* updateGrade query added
* updateQuestion returnRows fixed
* gradeTest little fix

- Added banUserCourse
(TestLine: http://localhost:8080/PDL/courseBanUser?courseID=90)
- System.out.println cleaning
- Castexception ArrayList to List
- Removing Payment

Edit: Ik mis waarschijnlijk wat web.xml referenties.