This PR squashes all commits in PR gravitystorm#2140, which can be cl…

…osed.

**Added rendering of tag tourism=wilderness_hut**

Added specific symbols for basic_hut and wilderness_hut vs. generic amenity=shelter.

Notice that this drop shall be consistent with the other push related to zooms, where alpine_hut symbol (the main one) is shown at zoom>=13.

To summarize, the following different kind of huts have specific symbols now:

- amenity=shelter, shelter_type=basic_hut (zoom>=13)
- amenity=shelter (only shown at zoom >=16)
- tourism=alpine_hut  (not modified within this drop)
- tourism=wilderness_hut (zoom>=13)

alpine_hut: symbols/alpinehut.p.16.png
wilderness_hut: symbols/wilderness_hut.svg
generic shelter: symbols/shelter-14.svg
amenity=shelter with shelter_type=basic_hut: symbols/basic_hut.svg

amenity-points.mss

@@ -27,8 +27,20 @@
     point-placement: interior;
   }
 
+  [feature = 'tourism_wilderness_hut'][zoom >= 13],
+  [feature = 'amenity_shelter']['shelter_type' = 'basic_hut'][zoom >= 14],
   [feature = 'amenity_shelter'][zoom >= 16] {
     marker-file: url('symbols/shelter-14.svg');
+    [feature = 'tourism_wilderness_hut'] {
+    	marker-file: url('symbols/wilderness_hut.svg');
+      marker-width: 13;
+      marker-height: 13;
+    }
+    ['shelter_type' = 'basic_hut'] {
+    	marker-file: url('symbols/basic_hut.svg');
+      marker-width: 13;
+      marker-height: 13;
+    }
     marker-fill: @transportation-icon;
     marker-placement: interior;
     marker-clip: false;
@@ -1674,6 +1686,7 @@
   [feature = 'tourism_hostel'][zoom >= 17],
   [feature = 'tourism_chalet'][zoom >= 17],
   [feature = 'tourism_guest_house'][zoom >= 17],
+  [feature = 'tourism_wilderness_hut'][zoom >= 13],
   [feature = 'tourism_camp_site'][zoom >= 17] {
     text-name: "[name]";
     text-size: 10;
@@ -2184,4 +2197,3 @@
     }
   }
 }
-