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/accounting.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.2" baseProfile="tiny" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 50 50" overflow="inherit">
+  <path d="M41 1h-32c-2.2 0 -4 1.8 -4 4v40c0 2.2 1.8 4 4 4h32c2.2 0 4 -1.8 4 -4v-40c0 -2.2 -1.8 -4 -4 -4zm-24 40c0 1.1 -0.9 2 -2 2h-4c-1.1 0 -2 -0.9 -2 -2v-1c0 -1.1 0.9 -2 2 -2h4c1.1 0 2 0.9 2 2v1zm0 -8c0 1.1 -0.9 2 -2 2h-4c-1.1 0 -2 -0.9 -2 -2v-1c0 -1.1 0.9 -2 2 -2h4c1.1 0 2 0.9 2 2v1zm0 -8c0 1.1 -0.9 2 -2 2h-4c-1.1 0 -2 -0.9 -2 -2v-1c0 -1.1 0.9 -2 2 -2h4c1.1 0 2 0.9 2 2v1zm12 16c0 1.1 -0.9 2 -2 2h-4c-1.1 0 -2 -0.9 -2 -2v-1c0 -1.1 0.9 -2 2 -2h4c1.1 0 2 0.9 2 2v1zm0 -8c0 1.1 -0.9 2 -2 2h-4c-1.1 0 -2 -0.9 -2 -2v-1c0 -1.1 0.9 -2 2 -2h4c1.1 0 2 0.9 2 2v1zm0 -8c0 1.1 -0.9 2 -2 2h-4c-1.1 0 -2 -0.9 -2 -2v-1c0 -1.1 0.9 -2 2 -2h4c1.1 0 2 0.9 2 2v1zm12 16c0 1.1 -0.9 2 -2 2h-4c-1.1 0 -2 -0.9 -2 -2v-1c0 -1.1 0.9 -2 2 -2h4c1.1 0 2 0.9 2 2v1zm0 -8c0 1.1 -0.9 2 -2 2h-4c-1.1 0 -2 -0.9 -2 -2v-1c0 -1.1 0.9 -2 2 -2h4c1.1 0 2 0.9 2 2v1zm0 -8c0 1.1 -0.9 2 -2 2h-4c-1.1 0 -2 -0.9 -2 -2v-1c0 -1.1 0.9 -2 2 -2h4c1.1 0 2 0.9 2 2v1zm0 -9c0 1.1 -0.9 2 -2 2h-28c-1.1 0 -2 -0.9 -2 -2v-8c0 -1.1 0.9 -2 2 -2h28c1.1 0 2 0.9 2 2v8z"/>
+</svg>