controllers.js: added check whether user is an organiser of the event in order to be able to choose or add questions for the event
controllers.js: added check whether user is an organiser of the event in order to be able to choose or add questions for the event

clemens-huebner/amos-ss16-proj8,clemens-huebner/amos-ss16-proj8,clemens-huebner/amos-ss16-proj8