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/wind_turbine.svg

@@ -0,0 +1,4 @@
+<?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="M8 6.25L8 14.5C8 14.85 7.85 15 7.5 15C7.16 15 7 14.85 7 14.5L7 8L8 6.25zM3.5 0.5C3.68 0.77 6.75 4.5 6.75 4.5L5 8.75C4.84 9.14 5 9.98 5.25 9.75C5.66 9.37 8 5 8 5L12 3.8C12.52 3.66 12.88 3 12.5 3C11.95 3 7.85 3.46 7.85 3.46L4.5 0.5C4.12 0.15 3.3 0.2 3.5 0.5z"/>
+</svg>