Fix page titles for poster management views

aleksis/apps/resint/templates/resint/poster/list.html

 {% extends "core/base.html" %}
 {% load static i18n rules %}
 
-{% block content %}
-
+{% block page_title %}
+  {% trans "Posters" %}
+{% endblock %}
+{% block browser_title %}
+  {% trans "Posters" %}
+{% endblock %}
 
-  <h1>{% trans "Posters" %}</h1>
+{% block content %}
   <div class="row">
     {% for group in poster_groups %}
       <div class="col s12 m6 l4 xl3">
@@ -71,7 +75,13 @@
             <i class="material-icons left">picture_as_pdf</i> {% trans "Show" %}
           </a>
 
-          {% has_perm "resint.delete_poster" user poster as can_delete_poster %}
+          {% has_perm "resint.edit_poster_rule" user poster as can_edit_poster %}
+          {% if can_edit_poster %}
+            <a class="btn-flat orange-text waves-effect waves-orange" href="{% url "poster_edit"  poster.id %}">
+              <i class="material-icons left">edit</i> {% trans "Edit" %}
+            </a>
+          {% endif %}
+          {% has_perm "resint.delete_poster_rule" user poster as can_delete_poster %}
           {% if can_delete_poster %}
             <a class="btn-flat red-text waves-effect waves-red" href="{% url "poster_delete"  poster.id %}">
               <i class="material-icons left">delete</i> {% trans "Delete" %}

aleksis/apps/resint/templates/resint/poster/upload.html

 {% extends 'core/base.html' %}
 {% load material_form i18n %}
 
-{% block content %}
-  <h4>{% blocktrans %}Upload poster{% endblocktrans %}</h4>
+{% block page_title %}
+  {% trans "Upload poster" %}
+{% endblock %}
+{% block browser_title %}
+  {% trans "Upload poster" %}
+{% endblock %}
 
+{% block content %}
   <form method="post" enctype="multipart/form-data">
     {% csrf_token %}
     {% form form=form %}{% endform %}