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/polished_nail.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" x="0" y="0" viewBox="0 0 15 15">
+  <path d="M11 6.5C11.5 9 12 11 12 15L11 15C11 12 10.5 9.5 10.5 9.5C10.5 9.5 10.5 12 7.5 12C4.5 12 4.5 9.5 4.5 9.5C4.5 9.5 4 12 4 15C4 15 3 15 3 15C3 11 3.5 9 4 6.5C4 2 4 0 7.5 0C11 0 11 2 11 6.5zM7.5 1C5 1 5 2.5 5 7C5.5 4 5.5 2 7.5 1z"/>
+</svg>