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/dog_shelter.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="M4 7L4 14L2 14L2 7.78L1 8.16L1 6L14 1L14 3.14L4 7ZM10.1 11.39L7.8 11.39L8.83 13.08C9 13.37 8.9 13.73 8.62 13.9C8.33 14.07 7.96 13.98 7.78 13.69L6.68 11.87L6.68 13.4C6.68 13.73 6.41 14 6.07 14C5.91 14 5.75 13.94 5.64 13.83C5.52 13.71 5.46 13.56 5.46 13.4L5.46 9.49L4.63 9.02C4.55 8.98 4.49 8.9 4.46 8.82C4.44 8.73 4.45 8.63 4.5 8.55C4.59 8.39 4.81 8.33 4.98 8.42L5.5 8.72L9.6 8.72L11.53 9.64L11.53 11.14C11.53 11.27 11.51 11.39 11.32 11.39L11.32 13.4C11.32 13.73 11.05 14 10.72 14C10.38 14 10.1 13.73 10.1 13.4L10.1 11.39ZM9.79 8.31L9.79 8.31L9.79 6L13.45 7.71L12.93 8.8L11.52 8.8L11.52 9.12L9.79 8.31Z"/>
+</svg>