Add configuration variable for base path

Wird verwendet, um die absoluten Pfade für Abb. in der Seitenleiste dynamischer zu handhaben.

_layouts/website/page.html

 {% extends template.self %}
 
 {% block body %}
-  <style>#forkongithub a{background:#c11;color:#fff;text-decoration:none;font-family:arial,sans-serif;text-align:center;font-weight:bold;padding:5px 40px;font-size:1rem;line-height:2rem;position:relative;transition:0.5s;}#forkongithub a:hover{background:#000;color:#fff;}#forkongithub a::before,#forkongithub a::after{content:"";width:100%;display:block;position:absolute;top:1px;left:0;height:1px;background:#fff;}#forkongithub a::after{bottom:1px;top:auto;}@media screen and (min-width:800px){#forkongithub{position:fixed;display:block;top:0;right:0;width:200px;overflow:hidden;height:200px;z-index:9999;}#forkongithub a{width:200px;position:absolute;top:45px;right:-50px;transform:rotate(45deg);-webkit-transform:rotate(45deg);-ms-transform:rotate(45deg);-moz-transform:rotate(45deg);-o-transform:rotate(45deg);box-shadow:4px 4px 10px rgba(0,0,0,0.8);}}</style><span id="forkongithub"><a target="_blank"  href="https://collaborating.tuhh.de/itbh/veranstaltungsskript-inf-sose2017">Fork me on GitLab</a></span>
+  <style>#forkongithub a{background:#c11;color:#fff;text-decoration:none;font-family:arial,sans-serif;text-align:center;font-weight:bold;padding:5px 40px;font-size:1rem;line-height:2rem;position:relative;transition:0.5s;}#forkongithub a:hover{background:#000;color:#fff;}#forkongithub a::before,#forkongithub a::after{content:"";width:100%;display:block;position:absolute;top:1px;left:0;height:1px;background:#fff;}#forkongithub a::after{bottom:1px;top:auto;}@media screen and (min-width:800px){#forkongithub{position:fixed;display:block;top:0;right:0;width:200px;overflow:hidden;height:200px;z-index:9999;}#forkongithub a{width:200px;position:absolute;top:40px;right:-50px;transform:rotate(45deg);-webkit-transform:rotate(45deg);-ms-transform:rotate(45deg);-moz-transform:rotate(45deg);-o-transform:rotate(45deg);box-shadow:4px 4px 10px rgba(0,0,0,0.8);}}</style><span id="forkongithub"><a target="_blank"  href="https://collaborating.tuhh.de/itbh/veranstaltungsskript-inf-sose2017">Fork me on GitLab</a></span>
 
     <div class="book">
     <div class="book-summary">
         <h2>{{ config.title }}</h2>
-        <img style="width: 90%"src="https://fizban05.rz.tu-harburg.de/itbh/veranstaltungsskript-inf-sose2017/abb/IBM_Electronic_Data_Processing_Machine_-_GPN-2000-001881_thumb.jpg" alt="Kursbild">
+        <img style="width: 90%"src="{{ config.base_path }}abb/IBM_Electronic_Data_Processing_Machine_-_GPN-2000-001881_thumb.jpg" alt="Kursbild">
         {% block book_sidebar %}
             {% block search_input %}{% endblock %}
             {% block book_summary %}

_layouts/website/summary.html

@@ -54,7 +54,7 @@
     <li class="divider"></li>
 </ul>
 <div class="license oer">
-  <img id="oer-logo" src="https://fizban05.rz.tu-harburg.de/itbh/veranstaltungsskript-inf-sose2017/abb/oer-logo.png" alt="Open Educational Resources">
+  <img id="oer-logo" src="{{ config.base_path }}abb/oer-logo.png" alt="Open Educational Resources">
 </div>
 <div class="license">
   <a target="_blank" rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/legalcode.de"><img alt="Creative Commons Lizenzvertrag" style="border-width:0" src="https://i.creativecommons.org/l/by-sa/4.0/88x31.png" /></a><br />Dieses Werk ist lizenziert unter einer <a target="_blank" rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/legalcode.de">Creative Commons Namensnennung - Weitergabe unter gleichen Bedingungen 4.0 International Lizenz</a>.

book.json

 {
+  "base_path": "https://fizban05.rz.tu-harburg.de/itbh/veranstaltungsskript-inf-sose2017/",
   "plugins":  [
         "image-captions", "downloadpdf", "-search"
   ],