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/warehouse.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" id="warehouse" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path d="M13.5,5c-0.0762,0.0003-0.1514-0.0168-0.22-0.05L7.5,2L1.72,4.93C1.4632,5.0515,1.1565,4.9418,1.035,4.685&#xA;&#x9;S1.0232,4.1215,1.28,4L7.5,0.92L13.72,4c0.2761,0.0608,0.4508,0.3339,0.39,0.61C14.0492,4.8861,13.7761,5.0608,13.5,5z M5,10H2v3h3&#xA;&#x9;V10z M9,10H6v3h3V10z M13,10h-3v3h3V10z M11,6H8v3h3V6z M7,6H4v3h3V6z"/>
+</svg>