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/lighthouse.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" id="lighthouse" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path d="M4.5,6L0,7V6.5l4.5-1V6z M4.5,3.5L0,2.5V3l4.5,1V3.5z M10.5,3.5V4L15,3V2.5L10.5,3.5z M10.5,6L15,7V6.5l-4.5-1V6z M8,7V2&#xA;&#x9;h2.5c0.2761,0.0552,0.5448-0.1239,0.6-0.4c0.0552-0.2761-0.1239-0.5448-0.4-0.6l-3-1C7.5696-0.0586,7.4204-0.0586,7.29,0l-3,1&#xA;&#x9;c-0.2761,0.0552-0.4552,0.3239-0.4,0.6S4.2139,2.0552,4.49,2H7v5H5l-2,7h9l-2-7H8z"/>
+</svg>