refactored json input processing
refactored json input processing

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