Make snow layers drop as the craft they are on moves

[eirikh1996]

Is your feature request related to a problem? Please describe. When adding snow as a passthrough block on a craft, they remain in the air despite having no support anymore. This can leave long trails of snow when cruising through snowy areas, and these trails are rather ugly

Describe the solution you'd like When the craft cruises, snow that forms on a moving craft or that has been un-phased will drop when it no longer has a block supporting it.