This may cause 'lagging' statistics, but that
should not be a problem.

change getQuestionsBySortOrder to fetch Questions in one single db request instead of requesting every document alone

Task #14410

It can occur that the timed event of piRound deactivation will not be
called (server crash/restart). With this fix the activation will be
canceled on question document when the endtime has been exceeded. Task
#14410

fix Parameter in getQuestionSortType and getSubjectSortType; Function expected the questionVariant, instead got a boolean(in a String)

#15391 add null-query to not get nullpointerexception and rework getQuestionBySortOrder and some minor bugs

#15362 alphabetical sortOrder is now automatically created when there is no sortOrder. bugfix included

#14886 edited the lecture/preparation view to use new sort_question-views, saveOrder is not checking whether there is already a list