Updated API for plugins.
Updated API for plugins.

CatoTH/OpenSlides,jwinzer/OpenSlides,ostcar/OpenSlides,emanuelschuetze/OpenSlides,emanuelschuetze/OpenSlides,FinnStutzenstein/OpenSlides,boehlke/OpenSlides,FinnStutzenstein/OpenSlides,rolandgeider/OpenSlides,emanuelschuetze/OpenSlides,tsiegleauq/OpenSlides,ostcar/OpenSlides,boehlke/OpenSlides,rolandgeider/OpenSlides,ostcar/OpenSlides,FinnStutzenstein/OpenSlides,normanjaeckel/OpenSlides,normanjaeckel/OpenSlides,CatoTH/OpenSlides,jwinzer/OpenSlides,jwinzer/OpenSlides,normanjaeckel/OpenSlides,boehlke/OpenSlides,CatoTH/OpenSlides,OpenSlides/OpenSlides,jwinzer/OpenSlides,rolandgeider/OpenSlides,normanjaeckel/OpenSlides,tsiegleauq/OpenSlides,CatoTH/OpenSlides,jwinzer/OpenSlides,tsiegleauq/OpenSlides,boehlke/OpenSlides,FinnStutzenstein/OpenSlides,emanuelschuetze/OpenSlides,OpenSlides/OpenSlides