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/pitch.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" id="pitch" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path d="M5,3C4.4477,3,4,2.5523,4,2s0.4477-1,1-1s1,0.4477,1,1S5.5523,3,5,3z M12.5,10H10L9,7L8,5.25L9,5l2.3,1l0,0&#xA;&#x9;c0.2761,0.1105,0.5895-0.0239,0.7-0.3S11.9761,5.1105,11.7,5l0,0L9,4H7L5,5L4,6H2.5C2.2239,6,2,6.2239,2,6.5S2.2239,7,2.5,7H5l1-1&#xA;&#x9;l1,2l-2,2v3.5C5,13.7761,5.2239,14,5.5,14S6,13.7761,6,13.5v-3.11L8,9l1,2h3.5c0.2761,0,0.5-0.2239,0.5-0.5S12.7761,10,12.5,10z"/>
+</svg>