Add Object::IsDirty function in the API.

src/objects.h

Index: src/objects.h
===================================================================
--- src/objects.h	(revision 2910)
+++ src/objects.h	(working copy)
@@ -1427,6 +1427,10 @@
 
   // Tells whether this object needs to be loaded.
   inline bool IsLoaded();
+  
+  // Returns true if this is an instance of an api function and has
+  // been modified since it was created.  May give false positives.
+  bool IsDirty();
 
   bool HasProperty(String* name) {
     return GetPropertyAttribute(name) != ABSENT;