Note that this is currently untested. :o

Introduced a new CouchDB view method, and a new field to divide
'skill_questions' into preparation, lecture, and flashcard
variants. The former question type 'flashcard' will be removed
soon.

question object.

saveQuestion, update(Question), getAnswers, saveAnswer, getMyAnswer.

Removed sessionKey from routes if it is not needed.
Changed sessionKey from PathVariable to RequestParam if still needed.
/session/{sessionKey}/question/* => /question/byaudience/*
Added redirections for legacy routes to LegacyController.

Removed sessionKey from routes if it is not needed.
Changed sessionKey from PathVariable to RequestParam if still needed.
/session/{sessionKey}/question/* => /question/bylecturer/*

Read, unread, and total count for interposed/feedback questions
implemented.

Task #4027: getQuestionById fixes if a list of answers exist which could
not morphed by self

check if session has this question and throw unauthorized exception if
not

add type of user account
adjust test for new user account type
UserServiceTest which test persistence of the maps