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/alcohol-shop.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" id="alcohol-shop" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path d="M14,4h-4v3.44l0,0c0,0,0,0,0,0.06c0.003,0.9096,0.6193,1.7026,1.5,1.93V13H11c-0.2761,0-0.5,0.2239-0.5,0.5&#xA;&#x9;S10.7239,14,11,14h2c0.2761,0,0.5-0.2239,0.5-0.5S13.2761,13,13,13h-0.5V9.43c0.8807-0.2274,1.497-1.0204,1.5-1.93c0,0,0,0,0-0.06&#xA;&#x9;l0,0V4z M13,7.5c0,0.5523-0.4477,1-1,1s-1-0.4477-1-1V5h2V7.5z M5.5,2.5V2C5.7761,2,6,1.7761,6,1.5S5.7761,1,5.5,1V0.5&#xA;&#x9;C5.5,0.2239,5.2761,0,5,0H4C3.7239,0,3.5,0.2239,3.5,0.5V1C3.2239,1,3,1.2239,3,1.5S3.2239,2,3.5,2v0.5C3.5,3.93,1,5.57,1,7v6&#xA;&#x9;c0,0.5523,0.4477,1,1,1h5c0.5318-0.0465,0.9535-0.4682,1-1V7C8,5.65,5.5,3.85,5.5,2.5z M4.5,12C3.1193,12,2,10.8807,2,9.5&#xA;&#x9;S3.1193,7,4.5,7S7,8.1193,7,9.5S5.8807,12,4.5,12z"/>
+</svg>