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/bulb.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="M8.5 11.5C8.5 11.5 6.5 11.5 6.5 11.5C6 11.5 6 9.5 5 8.5C4 7.5 3 6 3 4C3 1.5 5.5 0.5 7.5 0.5C9.5 0.5 12 1.5 12 4C12 6 11 7.5 10 8.5C9 9.5 9 11.5 8.5 11.5zM6.5 14C6.5 14 6.75 14 6.75 14C6.75 14 7 14.5 7.5 14.5C8 14.5 8.25 14 8.25 14C8.25 14 8.5 14 8.5 14C8.75 14 9 13.75 9 13.5C9 13.25 8.75 13 8.5 13L6.5 13C6.25 13 6 13.25 6 13.5C6 13.75 6.25 14 6.5 14zM8.5 11.75L6.5 11.75C6.25 11.75 6 12 6 12.25C6 12.5 6.25 12.75 6.5 12.75L8.5 12.75C8.75 12.75 9 12.5 9 12.25C9 12 8.75 11.75 8.5 11.75z"/>
+</svg>