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/police-JP.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg id="police-JP" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path d="M7.5,1A6.5,6.5,0,1,0,14,7.5,6.5,6.5,0,0,0,7.5,1Zm2.6,2.84L7.5,6.44,4.9,3.84A4.4428,4.4428,0,0,1,10.1,3.84ZM3.84,4.9007,6.4394,7.5l-2.6,2.5993A4.4429,4.4429,0,0,1,3.84,4.9007ZM4.9,11.16l2.6-2.6,2.6,2.6A4.4428,4.4428,0,0,1,4.9,11.16Zm6.26-1.0606L8.5606,7.5l2.6-2.5993a4.4429,4.4429,0,0,1-.0006,5.1986Z"/>
+</svg>