Timeslider: Display and Snap To Timestamps
If a source is not very dense, the timeslider should display ticks for each timestep available in the source. It should also be possible to snap to these timesteps and when using arrow-key-navigation, the next timestep should come from the source, not from calculation. If multiple layers are displayed, the timesteps don't necessarily line up, so either snapping modes should be invented, or it should just snap to the active layer.