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/power_circuit.svg

@@ -0,0 +1,5 @@
+<?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="M11.5 2C11.5 2 10 8 10 8C10 8 12 8 12 8C12 8 11 13 11 13C11 13 15 6 15 6C15 6 13 6 13 6C13 6 14.5 2 14.5 2C14.5 2 11.5 2 11.5 2z"/>
+  <path d="M3 1.5C3 0.75 3.75 0 4.5 0C5.25 0 6 0.75 6 1.5C6 2.25 5.25 3 4.5 3C3.75 3 3 2.25 3 1.5zM4.5 1C4.25 1 4 1.25 4 1.5C4 1.75 4.25 2 4.5 2C4.75 2 5 1.75 5 1.5C5 1.25 4.75 1 4.5 1zM4.5 13C4.75 13 5 13.25 5 13.5C5 13.75 4.75 14 4.5 14C4.25 14 4 13.75 4 13.5C4 13.25 4.25 13 4.5 13zM3 13.5C3 14.25 3.75 15 4.5 15C5.25 15 6 14.25 6 13.5C6 12.75 5.25 12 4.5 12C3.75 12 3 12.75 3 13.5zM4 3.5C4 3.5 4 11.5 4 11.5C4 12 5 12 5 11.5C5 11.5 5 3.5 5 3.5C5 3 4 3 4 3.5z"/>
+</svg>