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/temaki/tire.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0" y="0" viewBox="0 0 15 15">
+  <path d="M10 0C11.66 0 13 3.5 13 7.5C13 11.5 11.5 15 10 15C8.5 15 7 11.5 7 7.5C7 3.5 8.5 0 10 0C11.5 0 10 0 10 0zM10 2C9 2 8.5 4.5 8.5 7.5C8.5 10.5 9 13 10 13C11 13 11.5 10 11.5 7.5C11.5 5 11 2 10 2zM10 2.25C10.75 2.25 11.25 5 11.25 7.5C11.25 10 10.75 12.75 10 12.75C9.5 12.75 9.25 12 9.25 11.75C10 10.5 10 8 10 7.5C10 7 10 4.5 9.25 3.25C9.25 3 9.5 2.25 10 2.25zM9 0L5 0C3.5 0 2 3.5 2 7.5C2 11.5 3.5 15 5 15C5 15 9 15 9 15C7.5 14 6.5 11 6.5 7.5C6.5 4 7.5 1 9 0z"/>
+</svg>