how regionviews are built and maintained



iregion				iregionview
  end of parent_add, make
  iregiongroup child

iregiongroup			iregiongroupview
  monitor object updates,	  on iregiongroupview_refresh() create and 
  set and unset model->display	  destroy regionview ... watches iregion model


regionview_new( iregion, area, imagepresent )
  does not view_link(), since it's not a true view ... adds own signal 
  handlers for "changed" and "destroy" on iregion/iarrow



