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/gate.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 0.84375,2 C 0.5625,2.046875 0,2.25 0,3 l 0,9 2,0 0,-9 C 2,2 1,2 1,2 1,2 0.9375,1.984375 0.84375,2 z m 12,0 C 12.5625,2.046875 12,2.25 12,3 l 0,9 2,0 0,-9 C 14,2 13,2 13,2 13,2 12.9375,1.984375 12.84375,2 z M 3,4 l 0,7 8,0 0,-7 -8,0 z m 1.75,1 4.5,0 C 9.25,5 10,5 10,5.5 10,6 9.25,6 9.25,6 L 4.75,6 C 4.75,6 4,6 4,5.5 4,5 4.75,5 4.75,5 z m 0,2 4.5,0 C 9.25,7 10,7 10,7.5 10,8 9.25,8 9.25,8 L 4.75,8 C 4.75,8 4,8 4,7.5 4,7 4.75,7 4.75,7 z m 0,2 4.5,0 C 9.25,9 10,9 10,9.5 10,10 9.25,10 9.25,10 l -4.5,0 C 4.75,10 4,10 4,9.5 4,9 4.75,9 4.75,9 z"
+     id="gate"
+     style="fill:#000000;fill-opacity:1;stroke:none" />
+</svg>