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/toll_gantry.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg viewBox="0 0 15 15" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+  <path d="M14 3L13 3L13 4L13.5 4C13.78 4 14 4.22 14 4.5L14 5.5C14 5.78 13.78 6 13.5 6L11.5 6C11.22 6 11 5.78 11 5.5L11 4.5C11 4.22 11.22 4 11.5 4L12 4L12 3L9 3L9 4L9.5 4C9.78 4 10 4.22 10 4.5L10 5.5C10 5.78 9.78 6 9.5 6L7.5 6C7.22 6 7 5.78 7 5.5L7 4.5C7 4.22 7.22 4 7.5 4L8 4L8 3L5 3L5 4L5.5 4C5.78 4 6 4.22 6 4.5L6 5.5C6 5.78 5.78 6 5.5 6L3.5 6C3.22 6 3 5.78 3 5.5L3 4.5C3 4.22 3.22 4 3.5 4L4 4L4 3L3 3C2.45 3 2 3.45 2 4L2 14L0 14L0 4C0 2.34 1.34 1 3 1L14 1C14.55 1 15 1.45 15 2C15 2.55 14.55 3 14 3Z"/>
+</svg>