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/maki/toilet.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="15" height="15" viewBox="0 0 15 15" xmlns="http://www.w3.org/2000/svg" id="toilet">
+  <path d="M3 1.5a1.5 1.5 0 1 0 3 0 1.5 1.5 0 0 0-3 0ZM11.5 0a1.5 1.5 0 1 1 0 3 1.5 1.5 0 0 1 0-3ZM3.29 4a1 1 0 0 0-.868.504L.566 7.752a.5.5 0 1 0 .868.496l1.412-2.472A345.048 345.048 0 0 0 1 11h2v2.5a.5.5 0 0 0 1 0V11h1v2.5a.5.5 0 0 0 1 0V11h2L6.103 5.687l1.463 2.561a.5.5 0 1 0 .868-.496L6.578 4.504A1 1 0 0 0 5.71 4H3.29ZM9 4.5a.5.5 0 0 1 .5-.5h4a.5.5 0 0 1 .5.5v5a.5.5 0 0 1-1 0v4a.5.5 0 0 1-1 0v-4h-1v4a.5.5 0 0 1-1 0v-4a.5.5 0 0 1-1 0v-5Z"/>
+</svg>