Added model horizon, planning views and iterations to class diagram
Added model horizon, planning views and iterations to class diagram

nismod/smif,willu47/smif,tomalrussell/smif,willu47/smif,tomalrussell/smif,willu47/smif,nismod/smif,nismod/smif,tomalrussell/smif,willu47/smif,tomalrussell/smif,nismod/smif