Added 'required' support for TextFieldView.  Fixes Issue#520.
Added 'required' support for TextFieldView.  Fixes Issue#520.

foam-framework/foam,osric-the-knight/foam,osric-the-knight/foam,jacksonic/foam,mdittmer/foam,jlhughes/foam,foam-framework/foam,mdittmer/foam,foam-framework/foam,jacksonic/foam,jacksonic/foam,foam-framework/foam,mdittmer/foam,jlhughes/foam,jacksonic/foam,osric-the-knight/foam,jlhughes/foam,mdittmer/foam,jlhughes/foam,osric-the-knight/foam,foam-framework/foam