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/pin.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 0c-8.28 0 -15 6.66 -15 14.87c0 8.21 15 35.14 15 35.14s15 -26.92 15 -35.13c0 -8.21 -6.72 -14.87 -15 -14.87zm-0.05 19.31c-2.56 0 -4.63 -2.06 -4.63 -4.59c0 -2.53 2.07 -4.59 4.63 -4.59c2.56 0 4.63 2.05 4.63 4.59c0 2.53 -2.07 4.59 -4.63 4.59z"/>
+</svg>