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/furniture.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 3,2 C 2,2 1,3 1,4 3,4 4,5.5760463 4,7 l 6,0 C 10,5.4818344 11,4 13,4 13,3 12,2 11,2 z M 1,5 C 0,5 0,6 0,6 0,6.5181656 0.481834,7 1,7 l 0,3 c 0,0.645252 0.423351,1 1,1 l 0.5,0 c 0,0 0,1 1,1 1,0 1,-1 1,-1 l 5,0 c 0,0 0,1 1,1 1,0 1,-1 1,-1 l 0.5,0 c 0.509491,0 1,-0.48425 1,-1 l 0,-3 c 0.494613,0 1,-0.3876224 1,-1 0,0 0,-1 -1,-1 -1,0 -2,1 -2,3 L 3,8 C 3,6 2,5 1,5 z"
+     id="furniture"
+     style="fill:#000000;fill-opacity:1;stroke:none" />
+</svg>