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/storage_fermenter.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="M12 8C12 8 12 14.5 12 14.5C12 15 11 15 11 14.5C11 14.5 11 10 11 10C10.5 11 8.5 13 8.5 13C8 13.5 7 13.5 6.5 13C6.5 13 4.5 11 4 10C4 10 4 14.5 4 14.5C4 15 3 15 3 14.5C3 14.5 3 8 3 8C3.5 9.5 11.5 9.5 12 8zM7.5 4.5C8.3 4.5 9 5 9 5.5C9 6 8.3 6.5 7.5 6.5C6.7 6.5 6 6 6 5.5C6 5 6.7 4.5 7.5 4.5zM12 2C11 -0.5 4 -0.5 3 2C3 2 3 7 3 7C3 9 12 9 12 7C12 7 12 2 12 2z"/>
+</svg>