These classes could be used to replace methods from DAO class.

question. See commit 990eb9fe.

**/lecturerquestion/{questionId}/answer/ for free text answers.

**/lecturerquestion/{questionId}/answer/.

question object.

property set.

answers of the previous piRound were selected if no answer for the
current piRound had been saved.

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

countActiveUsers for reportActiveUserCountForSession as it was already
the case for reportSessionDataToClient.
Added check against null for session key in Socket.IO's disconnect
handler.
Logging adjustments for Socket.IO specific code.

prevent the Socket.IO server from stopping and cause a redeployment to
fail because of the still running server.

certificate errors with SSL.

(Jetty) environment.
Reduced logging for production environment.