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/shelter.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="shelter"
+     d="M 3.53125 0 L 2.53125 2 L 3 2 L 4.046875 0 L 3.53125 0 z M 7.53125 0 L 6.53125 2 L 7 2 L 8.046875 0 L 7.53125 0 z M 11.53125 0 L 10.53125 2 L 11 2 L 12.046875 0 L 11.53125 0 z M 1.0234375 1 L 0.0234375 3 L 0.4921875 3 L 1.5410156 1 L 1.0234375 1 z M 5.03125 1 L 4.03125 3 L 4.5 3 L 5.546875 1 L 5.03125 1 z M 9.03125 1 L 8.03125 3 L 8.5 3 L 9.546875 1 L 9.03125 1 z M 13.03125 1 L 12.03125 3 L 12.5 3 L 13.546875 1 L 13.03125 1 z M 3 4 L 0 7 L 1.5 7 L 1.5 14 L 3 14 L 3 7 L 11 7 L 11 14 L 12.5 14 L 12.5 7 L 14 7 L 11 4 L 3 4 z " style="fill:#000000;fill-opacity:1;stroke:none" />
+</svg>