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/compass.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.2" baseProfile="tiny" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 50 50" overflow="inherit">
+  <path d="M25 49c-13.23 0 -24 -10.77 -24 -24c0 -13.23 10.77 -24 24 -24c13.23 0 24 10.77 24 24c0 13.23 -10.77 24 -24 24zm0 -44c-11.03 0 -20 8.97 -20 20s8.97 20 20 20s20 -8.97 20 -20s-8.97 -20 -20 -20zm0.05 3.25s-7.04 12.07 -7.04 15.75v2c0 3.68 7.07 16 7.07 16s6.93 -12.07 6.93 -15.74v-2.26c0 -3.68 -6.95 -15.74 -6.95 -15.74zm-0.04 20.75c-2.21 0 -4 -1.79 -4 -4s1.79 -4 4 -4s4 1.79 4 4s-1.79 4 -4 4z"/>
+</svg>