40C3: tours, schedule data, tour map and calendar entries

- tour-map shortcode: Leaflet map of the tour locations with routes from the
  Congress, from the map/tours sections of data/schedule/<event>.yaml; Leaflet
  and the OSMIC, Maki and Temaki icon sets vendored; 39C3 uMap data converted.
- calendar shortcode: per tour date, a pill with an .ics download (iCalendar)
  and a Google Calendar link; Font Awesome Free vendored, fa-icon partial.
- README sections for the calendar and tour map shortcodes and the map data.

assets/vendor/icons/osmic/wilderness-hut.svg

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   version="1.1"
+   width="100%"
+   height="100%"
+   viewBox="0 0 14 14"
+   id="svg2">
+  <metadata
+     id="metadata8">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title></dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs6" />
+  <rect
+     width="14"
+     height="14"
+     x="0"
+     y="0"
+     id="canvas"
+     style="fill:none;stroke:none;visibility:hidden" />
+  <path
+     id="wilderness-hut"
+     d="M 8,0 8,2 7,1.5 0,5 0,7 1.5,6.3496094 1.5,14 3,14 3,5.6992188 7,4 8,4.4257812 8,9 4.5,9 c 0.025314,1.65157 -0.034277,3.38952 0,5 l 5,0 C 9.518206,11.046736 9.50603,8.0503867 9.5,5.0625 L 11,5.6992188 11,14 12.5,14 12.5,6.3496094 14,7 14,5 9.5,2.75 C 9.4984477,1.8314022 9.5,0.9158261 9.5,0 L 8,0 Z M 7,11 c 0,0 1,0 1,1 l 0,1 -2,0 0,-1 c 0,-1 1,-1 1,-1 z" style="fill:#000000;fill-opacity:1;stroke:none" />
+</svg>