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/briefcase_info.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="M5 4L10 4L10 3L5 3L5 4ZM4 4L4 3C4 2.45 4.45 2 5 2L10 2C10.55 2 11 2.45 11 3L11 4L13 4C13.55 4 14 4.45 14 5L14 12C14 12.55 13.55 13 13 13L2 13C1.45 13 1 12.55 1 12L1 5C1 4.45 1.45 4 2 4L4 4ZM5.5 7.5L6.75 8.75L6.75 10.75L5.5 12L9.5 12L8.25 10.75L8.25 7.5L5.5 7.5ZM7.5 7C8.05 7 8.5 6.55 8.5 6C8.5 5.45 8.05 5 7.5 5C6.95 5 6.5 5.45 6.5 6C6.5 6.55 6.95 7 7.5 7Z"/>
+</svg>