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/pipe.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="M14 2C15 2 14.5 3 14 3C12 3 11.5 3.5 10 7C8 11.5 6.75 13 3 13C0.5 13 0.5 11 0.5 10C0.5 9 0.5 8.25 0.75 7.5C1.25 7.75 1.75 8 3 8C4.25 8 4.75 7.75 5.25 7.5C5.5 8.25 5.5 9 5.5 10C5.5 10 7.5 9.5 9 6.5C10.5 3 11.5 2 14 2zM5 7C5 6.75 3 6.75 3 6.75C3 6.75 1 6.75 1 7C1 7.25 2 7.5 3 7.5C4 7.5 5 7.25 5 7z"/>
+</svg>