fix(core): drop webpage remains from template

The base template still contained a couple of references to variables
that stem from the webpage context processors. We don't use those
anymore, so lets get rid of those variables, to make the templates more
readable.

Closes: #410

apis_core/core/templates/base.html

@@ -50,8 +50,6 @@
     <link href="https://fonts.googleapis.com/css?family=Libre+Franklin:400,500"
           rel="stylesheet" />
 
-    {% if PROJECT_CSS %}<link rel="stylesheet" href="{{ PROJECT_CSS }}?rnd=1" rel="stylesheet" />{% endif %}
-
     {% block scriptHeader %}{% endblock %}
 
   </head>
@@ -71,14 +69,10 @@
           {% block nav-class %}navbar navbar-expand-lg navbar-light bg-light border-bottom mb-2 p-0{% endblock nav-class %}
            ">
           <div class="container-fluid">
-            <!-- Start custom branding -->
-            <a href="/"
-               class="navbar-brand custom-logo-link"
-               rel="home"
-               itemprop="url">
-              <img src="{{ PROJECT_LOGO }}" class="img-fluid" style="height: 36px;" />
-            </a>
-            <!-- End custom branding -->
+
+            {% block navbar-before %}
+            {% endblock navbar-before %}
+
             <button class="navbar-toggler"
                     type="button"
                     data-toggle="collapse"
@@ -186,19 +180,11 @@
       <!-- Start main content block -->
       <div id="content">
 
-        {% if DEV_VERSION %}
-          <div class="alert alert-danger" role="alert">
-            This is a DEVELOPMENT instance. Click <a href="https://{{ PROJECT_NAME }}.acdh.oeaw.ac.at">here</a> for the
-            Production version
-          </div>
-        {% endif %}
-
         {% block content %}{% endblock %}
 
       </div>
       <!-- End main content block -->
       <div class="d-flex footer-separator justify-content-center p-2"></div>
-      <!-- Start site footer -->
 
       {% block footer %}
         <div id="wrapper-footer-full" class="fundament-default-footer">
@@ -224,24 +210,12 @@
       {% endblock footer %}
 
       {% block imprint %}
-        <!-- Start imprint, project partners -->
         <div id="wrapper-footer-secondary"
              class="footer-imprint-bar p-2 text-center">
           <a href="/imprint.html">Imprint | Impressum</a>
-
-          {% if user.is_authenticated %}
-            {% if DB_NAME %}
-              <div class="footer-imprint-bar">
-                <div>{{ DB_NAME }}</div>
-              </div>
-            {% endif %}
-          {% endif %}
-
         </div>
       {% endblock imprint %}
 
-      <!-- End imprint, project partners -->
-      <!-- End site footer -->
     </div>
 
     {% block scripts %}