Fix some py3k warnings in the standard library.
diff --git a/Lib/shutil.py b/Lib/shutil.py
index 0cc9262..df571e7 100644
--- a/Lib/shutil.py
+++ b/Lib/shutil.py
@@ -10,6 +10,7 @@
 from os.path import abspath
 import fnmatch
 from warnings import warn
+import collections
 
 try:
     from pwd import getpwnam
@@ -500,7 +501,7 @@
     """
     if extra_args is None:
         extra_args = []
-    if not callable(function):
+    if not isinstance(function, collections.Callable):
         raise TypeError('The %s object is not callable' % function)
     if not isinstance(extra_args, (tuple, list)):
         raise TypeError('extra_args needs to be a sequence')