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/laundry.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" id="laundry" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path id="path3291-2" d="M8,1L6,3H3c0,0-1,0-1,1v9c0,1,1,1,1,1h9c0,0,1,0,1-1V2c0-1-1-1-1-1&#xA;&#x9;S8,1,8,1z M8.5,2h2C10.777,2,11,2.223,11,2.5S10.777,3,10.5,3h-2C8.223,3,8,2.777,8,2.5S8.223,2,8.5,2z M7.5,6&#xA;&#x9;c1.6569,0,3,1.3431,3,3s-1.3431,3-3,3s-3-1.3431-3-3S5.8431,6,7.5,6z"/>
+</svg>