404 Improvement

Bug fixes in timetable (issue #248)

Fill second date field automatically (issue #242, AUB)

Feature/german datepicker

Change email texts of support app to make them OTRS ready (issue #234)

Allow greater than character in LaTeX (issue #241)

Improve the design

- Mobile-optimize the upper box (and trim the text)
- adjust the position of the `print`-button
- some .idea changes
- hide some text on mobile phones

Improve rendering of plural names (issue #212) | Some design improves

Dev 1.0.1

Problem: If the start lesson equal to the end lesson, there was no lesson shown

Location: Event.create()
Problem: Got absence by id without filtering by term or school year
Solution: Use run_one of api.py, which filters automatically