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/water_tap.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg viewBox="0 0 15 15" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+  <path d="M8 2L8 3L9 3C10.1 3 11 3.9 11 5L11 14L9 14L9 5L6 5L6 7L6.5 7C6.78 7 7 7.22 7 7.5L7 8L3 8L3 7.5C3 7.22 3.22 7 3.5 7L4 7L4 5C4 4 5 3 6 3L7 3L7 2L5.5 2C5.22 2 5 1.78 5 1.5C5 1.22 5.22 1 5.5 1L9.5 1C9.78 1 10 1.22 10 1.5C10 1.78 9.78 2 9.5 2L8 2Z"/>
+</svg>