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/kerb-rolled.svg

@@ -0,0 +1,6 @@
+<?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" x="0" y="0" viewBox="0 0 15 15">
+  <path d="M0 5C6 5 8 9.5 8 12C8 12 8 14 8 14L0 14C0 14 0 5 0 5z"/>
+  <path d="M9 11L15 11L15 14L9 14L9 11z"/>
+  <path d="M8.23 2.24C8.23 2.24 9.5 1 9.5 1C9.5 1 12.32 4.07 12.32 4.07C12.32 4.07 14 2.5 14 2.5C14 2.5 14 7 14 7C14 7 9.5 7 9.5 7C9.5 7 10.99 5.31 10.99 5.31C10.99 5.31 8.23 2.24 8.23 2.24z"/>
+</svg>