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/temaki.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="M14.5 8.5C14 9.5 1 14 0.5 13.5C0 13 8.5 2.5 10 2C12.5 1.5 15.5 6.5 14.5 8.5zM10 2.5C9.5 4.5 12 8 14 8.5C15 6.5 12 2.5 10 2.5zM11.25 4C10.75 4.5 12.5 7 13 6.5C13.5 6 11.5 3.5 11.25 4z"/>
+</svg>