Added botton to download invitation

#179

server.py

@@ -835,6 +835,12 @@ def get_protocol_source(protocol):
         file_like, cache_timeout=1, as_attachment=True,
         attachment_filename="{}.txt".format(protocol.get_short_identifier()))
 
+@app.route("/protocol/invitation/<int:protocol_id>")
+@login_required
+@db_lookup(Protocol)
+@require_modify_right()
+def get_protocol_invitation(protocol):
+	return back.redirect("show_protocol", protocol_id=protocol.id)
 
 @app.route("/protocol/template/<int:protocol_id>")
 @login_required

templates/protocol-show.html

@@ -30,6 +30,7 @@
                     {% endif %}
                 {% endif %}
                 {% if not protocol.is_done() %}
+					<a class="btn btn-success" href="{{url_for("get_protocol_invitation", protocol_id=protocol.id)}}">Aushang</a>
                     <a class="btn btn-default" href="{{url_for("get_protocol_template", protocol_id=protocol.id)}}">Vorlage</a>
                     {% if config.MAIL_ACTIVE %}
                         <a class="btn btn-default" href="{{url_for("send_protocol_reminder", protocol_id=protocol.id, csrf_token=get_csrf_token())}}" onclick="return confirm('Bist du dir sicher, dass du manuell eine Einladung verschicken willst? Dies wird auch automatisch geschehen.');">Einladung versenden</a>