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/place-of-worship.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" id="place-of-worship" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path id="path9064" d="M7.5,0l-2,2v2h4V2&#xA;&#x9;L7.5,0z M5.5,4.5L4,6h7L9.5,4.5H5.5z M2,6.5c-0.5523,0-1,0.4477-1,1V13h2V7.5C3,6.9477,2.5523,6.5,2,6.5z M4,6.5V13h7V6.5H4z&#xA;&#x9; M13,6.5c-0.5523,0-1,0.4477-1,1V13h2V7.5C14,6.9477,13.5523,6.5,13,6.5z"/>
+</svg>