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/movie_rental.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="M25.51 22.57c-1.51 0 -2.74 1.23 -2.74 2.74c0 1.51 1.23 2.74 2.74 2.74c1.51 0 2.74 -1.23 2.74 -2.74c0 -1.51 -1.23 -2.74 -2.74 -2.74zm16.32 -18.5c0 -1.14 -0.93 -2.07 -2.07 -2.07h-29.68c-1.14 0 -2.07 0.93 -2.07 2.07v41.86c0 1.14 0.93 2.07 2.07 2.07h29.68c1.15 0 2.07 -0.93 2.07 -2.07v-41.86zm-16.32 34.34c-7.22 0 -13.1 -5.88 -13.1 -13.1c0 -7.22 5.88 -13.1 13.1 -13.1c7.22 0 13.1 5.88 13.1 13.1c0 7.23 -5.88 13.1 -13.1 13.1z"/>
+</svg>