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/prison.svg

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<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
+     d="M 0,0 0,14 14,14 14,0 0,0 z m 1,1 3,0 0,12 -0.5,0 0,-4.21875 C 3.200928,9.13501 3,9.5625 3,10 L 3,13 1,13 1,1 z m 4,0 4,0 0,12 -0.5,0 0,-5 -3,0 0,5 L 5,13 5,1 z m 5,0 3,0 0,12 -2,0 0,-3 C 11,9.5625 10.799072,9.13501 10.5,8.78125 L 10.5,13 10,13 10,1 z M 7,3 C 6.399152,3 5.866615,3.2680514 5.5,3.6875 l 0,2.625 C 5.866615,6.7319486 6.399152,7 7,7 7.600847,7 8.133385,6.7319486 8.5,6.3125 l 0,-2.625 C 8.133385,3.2680514 7.600847,3 7,3 z"
+     id="prison"
+     style="fill:#000000;fill-opacity:1;stroke:none" />
+</svg>