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/chimney.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="M10.5 0C12.5 0 14 1 14 2C14 3 12.5 4 10.5 4C9.5 4 9 3.75 9 3.75C9 5.5 6 5 6 5C6 5.5 5.5 6 4.5 6C3.5 6 3 5.5 3 5C3 4.5 3.5 4 4.5 4C4.5 3.5 4.5 2 7 2C7 1 8.5 0 10.5 0zM2 7C2 7 2 14.5 2 14.5C2 15 5 15 5 14.5C5 14.5 5 7 5 7C5 6.5 2 6.5 2 7z"/>
+</svg>