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/fighter_jet.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 48 48.00012" x="0px" y="0px">
+  <path d="M46 26a2 2 0 0 0 -2 2v3l-12 -9V17.48A2.49 2.49 0 0 0 28 15.51V10.63a3 3 0 0 0 -0.21 -1.11L25.1 0.74a1.18 1.18 0 0 0 -2.19 0L20.21 9.52A3 3 0 0 0 20 10.63v4.88a2.49 2.49 0 0 0 -4 1.97v4.52l-12 9v-3a2 2 0 0 0 -4 0v14a2 2 0 0 0 4 0v-2l16 -4v5l-4.45 3.81a1.87 1.87 0 0 0 1.32 3.19l7.12 -1l7.14 1a1.87 1.87 0 0 0 1.32 -3.19L28 41v-5l16 4v2a2 2 0 1 0 4 0v-14A2 2 0 0 0 46 26Z"/>
+</svg>