added beamlineService.watchBeamlineField() utility method, allow beamline items to callback their parent controller when shown
added beamlineService.watchBeamlineField() utility method, allow beamline items to callback their parent controller when shown

mkeilman/sirepo,radiasoft/sirepo,mrakitin/sirepo,radiasoft/sirepo,radiasoft/sirepo,mrakitin/sirepo,mkeilman/sirepo,radiasoft/sirepo,mkeilman/sirepo,radiasoft/sirepo,mkeilman/sirepo,mrakitin/sirepo,mrakitin/sirepo