Move out datengartens into their own section

- /datengarten/index.html returns a blog-like list
- /datengarten/index.ics returns a VCALENDAR
- /datengarten/index.xml returns a schedule.xml-style view

No more pretty rendering includes in the content pages,
some more cleanup in the front matter

layouts/datengarten/section.ics

@@ -0,0 +1,20 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//cccb//datengarten calendar//EN
+CALSCALE:GREGORIAN
+METHOD:PUBLISH
+{{range .Pages -}}
+BEGIN:VEVENT
+ORGANIZER;CN="CCCB":mailto:datengarten@berlin.ccc.de
+SUMMARY:{{.Title}}{{with .Params.subtitle}}: {{.}}{{end}}
+UID:{{.Params.no}}@datengarten.berlin.ccc.de
+SEQUENCE:0
+STATUS:CONFIRMED
+DTSTAMP:{{dateFormat "20060102T150405Z" .Params.event.start}}
+DTSTART;TZID=Europe/Berlin:{{dateFormat "20060102T150405" .Params.event.start}}
+DTEND;TZID=Europe/Berlin:{{dateFormat "20060102T150405" .Params.event.end}}
+LOCATION:{{with .Params.location}}{{.}}{{else}}CCCB{{end}}
+URL:{{.Permalink}}
+END:VEVENT
+{{end -}}
+END:VCALENDAR

layouts/datengarten/section.xml

@@ -0,0 +1,35 @@
+<schedule>
+  <version>1.0</version>
+  <conference>
+    <title>Datengarten</title>
+    <acronym>datengarten</acronym>
+    <days>99</days>
+    <start>2005-01-01</start>
+    <end>2099-12-31</end>
+    <timeslot_duration>2:00</timeslot_duration>
+  </conference>
+  {{range .Pages.ByDate -}}
+  <day index="{{.Params.no}}" date="{{dateFormat "2006-01-02" .Params.event.start}}" start="{{dateFormat "2006-01-02T15:04:05" .Params.event.start}}" end="{{dateFormat "2006-01-02T15:04:05" .Params.event.end}}">
+    <room name="Saal23">
+        <event id="{{.Params.no}}" guid="456fb60c-5ce7-11e8-be47-1fb2912eb8{{.Params.no}}">
+        <date>2016-11-23T13:00:00</date>
+        <start>13:00</start>
+	<duration>{{ $end := time .Params.event.end }}{{ $t := time "1970-01-01"}}{{ dateFormat "15:04" ( $t.Add ( $end.Sub (time .Params.event.start) ) ) }}</duration>
+        <room>Saal 23</room>
+        <slug>dg-{{.Params.no}}</slug>
+        <title>{{htmlEscape .Title}}</title>
+	<subtitle>{{with .Params.subtitle}}{{htmlEscape .}}{{end}}</subtitle>
+        <track/>
+        <type/>
+        <language>{{.Params.language}}</language>
+	<abstract>{{.Plain}}</abstract>
+	<description>{{.Plain}}</description>
+        <persons>
+            <person id="0">{{htmlEscape .Params.speaker}}</person>
+        </persons>
+        <links/>
+      </event>
+    </room>
+  </day> 
+  {{end -}}
+</schedule>

layouts/datengarten/single.html

@@ -0,0 +1,59 @@
+{{ define "main" }}
+<div class="container" role="main">
+  <div class="row">
+    <div class="col-lg-8 col-lg-offset-2 col-md-10 col-md-offset-1">
+      <article role="main" class="blog-post">
+	{{ partial "talk-infobox" . }}
+        {{ .Content }}
+
+        {{ if .Params.tags }}
+          <div class="blog-tags">
+            {{ range .Params.tags }}
+              <a href="{{ $.Site.LanguagePrefix | absURL }}/tags/{{ . | urlize }}/">{{ . }}</a>&nbsp;
+            {{ end }}
+          </div>
+        {{ end }}
+
+        {{ if .Site.Params.socialShare }}
+            <hr/>
+            <section id="social-share">
+              <ul class="list-inline footer-links">
+                {{ partial "share-links" . }}
+              </ul>
+            </section>
+        {{ end }}
+      </article>
+
+      {{ if ne .Type "page" }}
+        <ul class="pager blog-pager">
+          {{ if .PrevInSection }}
+            <li class="previous">
+              <a href="{{ .PrevInSection.Permalink }}" data-toggle="tooltip" data-placement="top" title="{{ .PrevInSection.Title }}">&larr; {{ i18n "previousPost" }}</a>
+            </li>
+          {{ end }}
+          {{ if .NextInSection }}
+            <li class="next">
+              <a href="{{ .NextInSection.Permalink }}" data-toggle="tooltip" data-placement="top" title="{{ .NextInSection.Title }}">{{ i18n "nextPost" }} &rarr;</a>
+            </li>
+          {{ end }}
+        </ul>
+      {{ end }}
+
+
+      {{ if (.Params.comments) | or (and (or (not (isset .Params "comments")) (eq .Params.comments nil)) (and .Site.Params.comments (ne .Type "page"))) }}
+        {{ if .Site.DisqusShortname }}
+          <div class="disqus-comments">
+            {{ template "_internal/disqus.html" . }}
+          </div>
+        {{ end }}
+        {{ if .Site.Params.staticman }}
+          <div class="staticman-comments">
+            {{ partial "staticman-comments.html" . }}
+          </div>
+        {{ end }}
+      {{ end }}
+
+    </div>
+  </div>
+</div>
+{{ end }}