add openstreetmap support

Fixes #27 (closed). A config flag is used to decide if openstreetmap should be used instead.

Set $config_use_openstreetmap = true; inside registration-system/config.local.php

registration-system/view/style.css

@@ -269,6 +269,7 @@ a.editenum { display: block; height: 20px; line-height: 20px; width: 20px; font-
     margin: 0px;
     padding: 0px;
     float: left;
+    background-color: #ffffff;
 }
 
 .fahrttable {