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/tree_palm.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 15 15">
+  <path d="M7 6.5C7 6.5 6 7.5 5.5 9.5C4 8 5.75 5.5 5.75 5.5C5.75 5.5 4.5 6 2 8.5C1.5 6 5 4.5 5 4.5C5 4.5 3 4.5 1 5C1 2.5 5.5 3 5.5 3C5.5 3 4.5 2 2 1.5C5 -0.5 7.5 2.5 7.5 2.5C7.5 2.5 8 0.5 12.5 1C10.5 2 9.5 3 9.5 3C9.5 3 13.5 3 14 6C12 5 9.5 4.5 9.5 4.5C9.5 4.5 12.5 6 12.5 9C11 7.5 9 6 9 6C9 6 9.5 8 9.5 9.5C9.5 11 9 12.5 8.5 14C8.5 14.5 6 14.5 6 14C6.5 12.5 7.5 11.5 7.5 9.5C7.5 7.5 7 6.5 7 6.5z"/>
+</svg>