Added support for DatePicker

Signed-off-by: René Meye <rene@meye.md>
Made Group creating clearer

Signed-off-by: René Meye <rene@meye.md>
A lecture now belongs to a course

Signed-off-by: René Meye <rene@meye.md>
Single Form

Signed-off-by: René Meye <rene@meye.md>
moved text to home file

Signed-off-by: René Meye <rene@meye.md>
Made a Redirect from a single form back to the single form

Signed-off-by: René Meye <rene@meye.md>
Merge branch 'refs/heads/develop' into ovgu-specific