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/army_tent.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg viewBox="0 0 15 15" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+  <path d="M9.5 15L7.5 9L5.5 15L1 15L1.41 12.94C1.8 10.99 2 9 2 7L2.75 6.81C4.81 6.3 6.55 4.9 7.5 3C8.45 4.9 10.19 6.3 12.25 6.81L13 7C13 9 13.2 10.99 13.59 12.94L14 15L9.5 15ZM3 9L3 11L4.5 11L5 9L3 9ZM10 9L10.5 11L12 11L12 9L10 9ZM7.5 0L12 0L10.5 1.5L12 3L7.5 3L7.5 0Z"/>
+</svg>