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/detergent_bottle.svg

@@ -0,0 +1,5 @@
+<?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" viewBox="0 0 15 15">
+  <path d="M9 2.5C9.25 2.5 9.25 3 9 3C8.75 3.25 5.75 3.25 5.5 3C5.25 3 5.25 2.5 5.5 2.5C5.75 2.5 6 2.5 6 2.5C6 2.5 6 1.5 6 1C6 0.5 8.5 0.5 8.5 1C8.5 1.5 8.5 2.5 8.5 2.5C8.5 2.5 8.75 2.5 9 2.5z"/>
+  <path d="M9 3.5C8.5 3.75 6 3.75 5.5 3.5C5.06 3.5 4 4.5 4 5C4 5.5 4 13.5 4 14C4 14.5 12 14.5 12 14C12 13.5 12 8.5 12 8.5C12 6 10.5 3.5 9 3.5zM9.75 8.5C9.5 8.25 9.25 7.25 9.25 6.25C9.25 5 9.75 4.75 10 5.25C10.5 6 11 7.25 11 8.5C11 9.25 10 9 9.75 8.5z"/>
+</svg>