Add generic datepicker support
Any date(time) field now automatically has a picker widget.
Patch by: "Haoyu Bai" <baihaoyu@gmail.com>
Rebased by: Sverre Rabbelier
Reviewed by: To-Be-Reviewed
Benjamin Niemann <pink at odahoda dot de>: Main developer of Python target.
Clinton Roy <clinton.roy at gmail dot com>: AST templates and runtime.