ObjectPicker JS: initialize dynamically-created widgets to show static labels. Fixes #1880
Framework (getRenderer): allow "txt" extension. Refs #470
Framework (dispatch): log RunTime exceptions.
XhtmlWidget (labeledControlTag): small code refactor. Refs #470
NethPlatform (createValidator): added NONNEGATIVE_INTEGER predefined validator. Refs #470
jquery.nethgui.button.js: honour "keepdisabled" CSS class. Refs #470
jquery.nethgui.base.js (ajaxMessage): added formatSuffix parameter, legacy default is "json". Refs #470