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/stamp.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="M14 1C14 1 14 2.5 14 2.5C13.25 2.5 13.25 4 14 4C14 4 14 5.25 14 5.25C13.25 5.25 13.25 6.75 14 6.75C14 6.75 14 8.25 14 8.25C13.25 8.25 13.25 9.75 14 9.75C14 9.75 14 11 14 11C13.25 11 13.25 12.5 14 12.5C14 12.5 14 14 14 14C14 14 12.5 14 12.5 14C12.5 13.25 11 13.25 11 14C11 14 9.75 14 9.75 14C9.75 13.25 8.25 13.25 8.25 14C8.25 14 6.75 14 6.75 14C6.75 13.25 5.25 13.25 5.25 14C5.25 14 4 14 4 14C4 13.25 2.5 13.25 2.5 14C2.5 14 1 14 1 14C1 14 1 12.5 1 12.5C1.75 12.5 1.75 11 1 11C1 11 1 9.75 1 9.75C1.75 9.75 1.75 8.25 1 8.25C1 8.25 1 6.75 1 6.75C1.75 6.75 1.75 5.25 1 5.25C1 5.25 1 4 1 4C1.75 4 1.75 2.5 1 2.5C1 2.5 1 1 1 1C1 1 2.5 1 2.5 1C2.5 1.75 4 1.75 4 1C4 1 5.25 1 5.25 1C5.25 1.75 6.75 1.75 6.75 1C6.75 1 8.25 1 8.25 1C8.25 1.75 9.75 1.75 9.75 1C9.75 1 11 1 11 1C11 1.75 12.5 1.75 12.5 1C12.5 1 14 1 14 1zM12 3C12 3 3 3 3 3L3 12L12 12C12 12 12 3 12 3zM11 4L11 11L4 11L4 4L11 4z"/>
+</svg>