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/teahouse.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="15" height="15" viewBox="0 0 15 15" xmlns="http://www.w3.org/2000/svg" id="teahouse">
+  <path d="M8.00002 5C8.00002 5 10 4.9 10 3.4 10 2.46598 9.17751 2.20864 8.47606 1.98917 7.95458 1.82601 7.5 1.68378 7.5 1.3 7.5.386843 8 0 8 0 8 0 7 .531581 7 1.5 7 2.21063 7.54045 2.46176 8.05947 2.70292 8.53888 2.92568 9 3.13994 9 3.7 9 4.7 8.00002 5 8.00002 5ZM11.8372 6.67447C11.3755 8.62063 10.7854 11.1073 9 12V14H6V12C4.21455 11.1073 3.62454 8.62063 3.16276 6.67447 3.10728 6.44061 3.05364 6.21455 3 6H12C11.9464 6.21453 11.8927 6.44063 11.8372 6.67447ZM6.99998 4C6.99998 5 5.49998 5 5.49998 5 5.49998 5 6.29295 4.9 6.29295 4.3 6.29295 4.02526 6.01604 3.85489 5.71852 3.67184 5.37315 3.45935 5 3.22977 5 2.8 5 1.9661 5.99998 1.5 5.99998 1.5 5.99998 1.5 5.49998 1.77344 5.49998 2.5 5.49998 2.88823 5.85322 3.04095 6.21687 3.19818 6.60257 3.36494 6.99998 3.53675 6.99998 4Z"/>
+</svg>