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/drag_lift.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="M6.51 1.37C6.57 0.88 6.99 0.5 7.5 0.5C7.92 0.5 8.28 0.76 8.43 1.13L13.44 0.5C13.71 0.47 13.96 0.66 14 0.94C14.03 1.21 13.84 1.46 13.56 1.5L8.5 2.13L8.5 4.5C8.5 4.87 8.3 5.19 8 5.37L8 14C8 14.28 7.78 14.5 7.5 14.5C7.22 14.5 7 14.28 7 14L7 5.37C6.7 5.19 6.5 4.87 6.5 4.5L6.5 2.38L1.56 3C1.29 3.03 1.04 2.84 1 2.56C0.97 2.29 1.16 2.04 1.44 2L6.51 1.37Z"/>
+</svg>