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/maki/bar.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" id="bar" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path id="path4" d="M7.5,1c-2,0-7,0.25-6.5,0.75L7,8v4&#xA;&#x9;c0,1-3,0.5-3,2h7c0-1.5-3-1-3-2V8l6-6.25C14.5,1.25,9.5,1,7.5,1z M7.5,2c2.5,0,4.75,0.25,4.75,0.25L11.5,3h-8L2.75,2.25&#xA;&#x9;C2.75,2.25,5,2,7.5,2z"/>
+</svg>