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/windmill.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 2.71875,0 1,1.71875 5.96875,6 1,10.28125 2.71875,12 7,7.03125 11.28125,12 13,10.28125 8.03125,6 13,1.71875 11.28125,0 7,4.96875 2.71875,0 z M 7,2 C 6.5846058,2 6.2371923,2.0902004 5.9375,2.21875 L 7,3.4375 8.0625,2.21875 C 7.7644902,2.0832701 7.4104059,2 7,2 z M 7,5.5 C 7.2761424,5.5 7.5,5.7238576 7.5,6 7.5,6.2761424 7.2761424,6.5 7,6.5 6.7238576,6.5 6.5,6.2761424 6.5,6 6.5,5.7238576 6.7238576,5.5 7,5.5 z M 4.1875,5.78125 4.15625,6.25 4.4375,6 4.1875,5.78125 z m 5.625,0 L 9.5625,6 9.84375,6.25 9.8125,5.78125 z M 7,8.5625 3.625,12.46875 3.5,14 10.5,14 10.375,12.46875 7,8.5625 z"
+     id="windmill"
+     style="fill:#000000;fill-opacity:1;stroke:none" />
+</svg>