IE8 does not support Object.defineProperty on non-DOM objects

(see http://stackoverflow.com/questions/3830800/object-defineproperty-in-es5)

lib/util.js

@@ -104,14 +104,22 @@ exports.defineSecureProp = function( obj, prop, value )
     }
     else
     {
-        Object.defineProperty( obj, prop,
+        try
         {
-            value: value,
+            Object.defineProperty( obj, prop,
+            {
+                value: value,
 
-            enumerable:   false,
-            writable:     false,
-            configurable: false,
-        });
+                enumerable:   false,
+                writable:     false,
+                configurable: false,
+            });
+        }
+        catch ( e )
+        {
+            // if there's an error (ehem, IE8), fall back
+            obj[ prop ] = value;
+        }
     }
 }