.uncatalogObject(): Raise exception on attempt to uncatalog id not in catalog.

lib/python/Products/ZCatalog/Catalog.py

@@ -368,7 +368,7 @@ class Catalog(Persistent, Acquisition.Implicit):
 
         """
         if uid not in self.uids.keys():
-            return
+            raise ValueError, "Uncatalog of absent id %s" % `uid`
         
         rid = self.uids[uid]