histedit: raise ImportError when demandloading is enabled stable

histedit: raise ImportError when demandloading is enabled

--- a/hgext/histedit.py	Sat Jun 01 17:10:24 2013 -0500
+++ b/hgext/histedit.py	Wed Jun 05 21:16:49 2013 +0200
@@ -140,6 +140,7 @@
 
 try:
     import cPickle as pickle
+    pickle.dump # import now
 except ImportError:
     import pickle
 import os