fix some non-fatal warnings

lib/phast/server/System.inc.php

@@ -170,10 +170,13 @@
 					return System::$TenantName;
 				}
 				else
+				{
+					if (isset($_SESSION["CurrentTenantName"]))
 					{
 						return $_SESSION["CurrentTenantName"];
 					}
 				}
+			}
 			return null;
 		}
 		

lib/phast/server/WebControl.inc.php

@@ -54,6 +54,9 @@
 		public $MaximumWidth;
 		public $MaximumHeight;
 
+		public $PhysicalFileName;
+		
+		public $VirtualTagPath;
 		public $Visible;
 		
 		/**

lib/phast/server/WebControls/AdditionalDetailWidget.inc.php

@@ -39,7 +39,7 @@
 		
 		public $ClassTitle;
 		
-		public function __construct($id)
+		public function __construct()
 		{
 			parent::__construct();