jsifyChildren: update logic, add doc comment
jsifyChildren: update logic, add doc comment

cleandart/react-dart,evanweible-wf/react-dart,evanweible-wf/react-dart,evanweible-wf/react-dart,evanweible-wf/react-dart,cleandart/react-dart,cleandart/react-dart,cleandart/react-dart