Adding support for slipway ways

[kocio-pl]

Resolves #484.

I'm not 100% sure about rendering names for ways, it's safer to skip it, since it's not clear if name label belongs to a slipway or a highway.

[kocio-pl]

Are there any other linear amenities which should be shown on osm-carto?

[daganzdaanda]

Is this the same as highway=service? Maybe use the narrower styling like in service=parking_aisle? Slipways are normally not very long, and should not look too important IMHO.

Are there any other linear amenities which should be shown on osm-carto?

#1890 is about benches

[kocio-pl]

Thanks for both suggestions! However our road code is spaghetti-esque and I'm still not able to find out where should I add another type of service road... Could someone help me find where it's selected?

[kocio-pl]

OK, it works, but it's better if someone would check the SQL for casing and filling:

[kocio-pl]

#1890 is about benches

I can think also about bus stops and I even think I saw it lately among other osm-carto issues, but forgot where it was mentioned.

[sommerluk]

I suppose that slipways have no own z_order value, and this could be a problem when sorting?

[kocio-pl]

I don't know, but it's hard for me to imagine that such specialized service road is crossing with other road on a different level.

[kocio-pl]

For me it's safe to be merged. Any comments or reviews?

[pnorman]

I don't know, but it's hard for me to imagine that such specialized service road is crossing with other road on a different level.

z_order isn't about different layers, it's within the same layer.

Are we requiring highway=service to render the white line?

[kocio-pl]

I meant physical levels, not our internal level/layer.

For me this is a special service road (which ends up in water), but still just a service road, so I expect no rendering changes. Do you have some other suggestion?

[kocio-pl]

@pnorman Do you still have some questions about this? I would merge it soon.