Merge branch 'kevin_local' into 'dennis_local'

.idea/dbnavigator.xml

.idea/modules.xml

notenmanager.iml

src/Calcuable.java

src/Course.java

src/CoursesOfStudy.java

src/Enrollment.java

src/Lecturer.java

src/Main.java

src/Student.java

src/UniversityMember.java

src/enumeration/BachelorDegree.java

src/enumeration/BachelorSemester.java

src/enumeration/CourseType.java

src/enumeration/ExamType.java

src/enumeration/FieldOfStudy.java

src/enumeration/Gender.java

src/enumeration/Mark.java

src/enumeration/Status.java