Openstreetmap-carto: Distinguish different cranes types

[Tomasz-W]

Follow up for https://github.com/gravitystorm/openstreetmap-carto/issues/3478 and https://github.com/gravitystorm/openstreetmap-carto/pull/3501. Distinguish different cranes types to show people better what they can expect in certain place.

• man_made=crane + crane:type=portal_crane:
  
• man_made=crane +crane:type=floor-mounted_crane:
  or (generic icon)
• man_made=crane + crane:type=travel_lift and crane:type=gantry:
  

Gist link: https://gist.github.com/Tomasz-W/ed6c01e147616e786faff2690fcce686

[matthijsmelissen]

This is going in too much detail for this stylesheet. Icons are meant to be pictograms, and do not need to be a literal depiction of the object in question.

[Adamant36]

@matthijsmelissen, you know that could apply to 99% of the icons being used right? For me its less about adding a "literal depiction of the object" and more about incentivising sub tagging by giving the sub tags their own icons. Which I think this accomplishes.

Also, I would venture that in a lot of cases people don't even know a sub tag exists or look it up on the wiki without it having unique icons. Personally, I wouldn't know about a lot of the sub-tags if there wasn't "to much detail" on the map by them having icons (different types of tourist information mediums comes to mind).

[sommerluk]

Let me add to what @matthijsmelissen said that the subtypes have all lower usage than 1000.

Closing as per @matthijsmelissen

[Adamant36]

@Sommerluck, crane:type=gantry has 864 uses. Alone I doubt that the extra 136 uses to get it to 1000 really matters, but since its being combined with crane:type=travel_lift which has 327 uses its over 1000. So I'll probably do a PR on it anyway even if this issue is closed. For good measure I'll add crane:type=portal_crane to it also since it has 991 uses. You and @matthijsmelissen can feel free to split hairs over the missing 9 uses in that case.