Add form for generating credits

Fixes #798
Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/html/translation.html

@@ -56,6 +56,9 @@
       {% if autoform %}
       <li><a href="#auto" data-toggle="tab">{% trans "Automatic translation" %}</a></li>
       {% endif %}
+      {% if user_can_view_reports %}
+      <li><a href="#reports" data-toggle="tab">{% trans "Translation reports" %}</a></li>
+      {% endif %}
     </ul>
   </li>
 {% if enable_sharing %}
@@ -189,6 +192,24 @@
 </div>
 {% endif %}
 
+{% if user_can_view_reports %}
+<div class="tab-pane" id="reports">
+<form action="{% url 'credits' project=object.subproject.project.slug subproject=object.subproject.slug %}" method="post" enctype="multipart/form-data">
+<div class="panel panel-primary">
+<div class="panel-heading"><h4 class="panel-title">{% trans "Credits" %}</h4></div>
+<div class="panel-body">
+<p>{% trans "Credits list all translators who have contributed to this component in given time period. It can be useful for including in your documentation or application to thanks to translators." %}</p>
+{% csrf_token %}
+{{ credits_form|crispy }}
+</div>
+<div class="panel-footer">
+<input type="submit" value="{% trans "Process" %}" class="btn btn-default" />
+</div>
+</div>
+</form>
+</div>
+{% endif %}
+
 {% if perms.trans.upload_translation %}
 <div class="tab-pane" id="upload">
 <form action="{% url 'upload_translation' project=object.subproject.project.slug subproject=object.subproject.slug lang=object.language.code %}" method="post" enctype="multipart/form-data">