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-raised.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 1L8 1L8 14L0 14L0 1z"/>
+  <path d="M9 11L15 11L15 14L9 14L9 11z"/>
+  <path d="M11 1C11 1 13 1 13 1C13 1 13 5 13 5C13 5 15 5 15 5C15 5 12 9 12 9C12 9 9 5 9 5C9 5 11 5 11 5C11 5 11 1 11 1z"/>
+</svg>