Add poi icon for silo

data/presets/presets.json

@@ -7765,6 +7765,7 @@
             "name": "Pumping Station"
         },
         "man_made/silo": {
+            "icon": "poi-silo",
             "fields": [
                 "building_area",
                 "crop"

data/presets/presets/man_made/silo.json

@@ -1,4 +1,5 @@
 {
+    "icon": "poi-silo",
     "fields": [
         "building_area",
         "crop"

svg/iD-sprite.json

@@ -283,12 +283,14 @@
     "poi-beach":                { "viewBox": "430 335 15 15" },
     "poi-fountain":             { "viewBox": "445 335 15 15" },
     "poi-storage-tank":         { "viewBox": "460 335 15 15" },
+    "poi-silo":                 { "viewBox": "475 335 15 15" },
 
     "poi-vending-machine-shape":   { "fill": "currentColor" },
     "poi-dice-shape":              { "fill": "currentColor" },
     "poi-beach-shape":             { "fill": "currentColor" },
     "poi-fountain-shape":          { "fill": "currentColor" },
     "poi-storage-tank-shape":      { "fill": "currentColor" },
+    "poi-silo-shape":              { "fill": "currentColor" },
 
     "turn-yes":                 { "viewBox": "200 320 44 24" },
     "turn-no":                  { "viewBox": "244 320 44 24" },

svg/iD-sprite.src.svg

@@ -232,6 +232,9 @@
     </g>
   </g>
   <g id="poi">
+    <g id="poi-silo">
+      <path d="M480,338.997 C480,340.247 485,340.497 485,338.997 C485,336.997 485,346.997 485,347.997 C485,349.497 480,349.497 480,347.997 C480,346.997 480,336.997 480,338.997 z M480.25,338.497 C480.25,339.569 484.75,339.626 484.75,338.554 C484.75,334.997 480.25,334.997 480.25,338.497 z" fill="#000000" id="poi-silo-shape"/>
+    </g>
     <g id="poi-storage-tank">
       <path d="M463,338.5 C463,340.5 472,340.5 472,338.5 C472,336.5 472,346.5 472,347.5 C472,349.5 463,349.5 463,347.5 C463,346.5 463,336.5 463,338.5 z M463.25,337.5 C463.25,339.5 471.75,339.5 471.75,337.5 C471.75,335.5 463.25,335.5 463.25,337.5 z" fill="#000000" id="poi-storage-tank-shape"/>
     </g>