improved type exception messages, added new elegant types
improved type exception messages, added new elegant types

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