For the c++ api dox this expands to "\c nullptr" (the
\c directive indicates a code literal value), and for sipify/Python
it expands to ``None`` (`` is sphinx annotation for literal values)
Makes for nicer dox for both c++ and Python!
- Adding datasets to mesh layer from properties panel
- Information and source panel in properties panel
- Selection of active dataset (properties or styling panel)
- Styling of contours/scalars (properties or styling panel)
- Styling of mesh frame (properties or styling panel)
- Styling of vector arrows (properties or styling panel)
