Add the ability to display axes in the volume renderer

Also, the camera can be flipped over if your data is from Australia.
Following up on the minor-ticks comment, could you add
```
                x_axis_minor_tick_visibility=False,
                y_axis_minor_tick_visibility=False,
                z_axis_minor_tick_visibility=False,
 ```
Or I guess it might be better to define a `show_minor_ticks` trait.