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/kerb-flush.svg

@@ -0,0 +1,6 @@
+<?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="M0 10L8 10L8 14L0 14L0 10z"/>
+  <path d="M9 11L15 11L15 14L9 14L9 11z"/>
+  <path d="M6 5C6 5 6 3 6 3C6 3 10 3 10 3C10 3 10 1 10 1C10 1 14 4 14 4C14 4 10 7 10 7C10 7 10 5 10 5C10 5 6 5 6 5z"/>
+</svg>