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/plumber.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" x="0" y="0" viewBox="0 0 15 15">
+  <path d="M7 3C7 3 7 6 7 6C7 6.5 6 6.5 6 6C6 6 2.5 6 2.5 6C1.5 6 1 5.5 1 4.5C1 4.5 1 1 1 1C0.5 1 0.5 0 1 0C1.5 0 4 0 4 0C4.5 0 4.5 1 4 1C4 1 4 2.5 4 2.5C4 2.5 4 3 4.5 3C4.5 3 6 3 6 3C6 2.5 7 2.5 7 3zM14 10C14.5 10 14.5 9 14 9C14 9 14 4.5 14 4.5C14 3.5 13.5 3 12.5 3C12.5 3 9 3 9 3C9 2.5 8 2.5 8 3C8 3 8 6 8 6C8 6.5 9 6.5 9 6C9 6 10.5 6 10.5 6C11 6 11 6.5 11 6.5C11 6.5 11 9 11 9C10.5 9 10.5 10 11 10C11 10 14 10 14 10z"/>
+  <path d="M12.5 10.5C12.75 10.5 14.25 12.25 14.25 13.5C14.25 14.5 13.25 15 12.5 15C11.75 15 10.75 14.5 10.75 13.5C10.75 12.25 12.25 10.5 12.5 10.5zM11.15 13.5C11.15 14.1 11.75 14.7 12.5 14.7C11.75 14.4 11.45 14.1 11.15 13.5z"/>
+</svg>