add support for animated models
add support for animated models

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