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/tennis.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg id="tennis" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path d="M13.1284,1.87c-1.5418-1.5406-4.5535-.7759-6.28,1.05a6.8282,6.8282,0,0,0-1.88,4.4,5.7275,5.7275,0,0,1-.57,2.72.6814.6814,0,0,0-.67.17l-2.49,2.5a.6941.6941,0,0,0,0,.98l.07.07a.7051.7051,0,0,0,.98,0l2.5-2.49a.683.683,0,0,0,.18-.66,8.5694,8.5694,0,0,1,3.12-.58,6.5487,6.5487,0,0,0,3.99-1.87C14.1084,6.13,14.579,3.3194,13.1284,1.87Zm-2.2-.04a2.3071,2.3071,0,0,1,1.64.61,2.548,2.548,0,0,1,.5,2.44l-2.95-2.96A3.8648,3.8648,0,0,1,10.9284,1.83Zm-4.57,6.81a2.6485,2.6485,0,0,1-.48-2.55l3.04,3.04A2.8522,2.8522,0,0,1,6.3584,8.64Zm2.88.39-3.26-3.27a5.1623,5.1623,0,0,1,.49-1.08l3.85,3.85A5.5093,5.5093,0,0,1,9.2384,9.03Zm1.34-.66-3.94-3.95a5.2032,5.2032,0,0,1,.74-.9l4.1,4.1A5.6869,5.6869,0,0,1,10.5784,8.37Zm1.11-.96-4.1-4.1a5.5714,5.5714,0,0,1,.84-.65l3.92,3.92A5.7187,5.7187,0,0,1,11.6884,7.41Zm.82-1.09L8.6984,2.5a4.1707,4.1707,0,0,1,1.09-.48l3.2,3.2A5.5656,5.5656,0,0,1,12.5084,6.32Z"/>
+</svg>