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/maki/toll.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" id="toll" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path d="M2.5 1C2.22386 1 2 1.22386 2 1.5V2V13H1.5C1.22386 13 1 13.2239 1 13.5C1 13.7761 1.22386 14 1.5 14H8.5C8.77614 14 9 13.7761 9 13.5C9 13.2239 8.77614 13 8.5 13H7V10.0987L13.7761 5.54576C14.0053 5.39175 14.0663 5.08109 13.9123 4.85189L13.6334 4.43687C13.4794 4.20766 13.1688 4.1467 12.9396 4.3007L7 8.29152V2H7.5C7.77614 2 8 1.77614 8 1.5C8 1.22386 7.77614 1 7.5 1H2.5ZM3 3.5C3 3.22386 3.22386 3 3.5 3H5.5C5.77614 3 6 3.22386 6 3.5V7.5C6 7.77614 5.77614 8 5.5 8H3.5C3.22386 8 3 7.77614 3 7.5V3.5Z"/>
+</svg>