Add support to connect to server via unix socket

The syntax for AddServer command and config is chosen to be unix:/path or unix:ssl:/path

For security reasons, only admins can add such servers, to prevent users from poking around the file system.

modules/data/webadmin/tmpl/add_edit_network.tmpl

@@ -5,6 +5,7 @@
 
 <script>
 	var NetworkEdit = <? VAR NetworkEdit ?>;
+	var EditUnixSockets = <? VAR EditUnixSockets ?>;
 </script>
 
 <div class="section">