Fixes issue #85. Also moves all json imports to go through oauth2client.anyjson.  Reviewed in http://codereview.appspot.com/5531064/.
diff --git a/oauth2client/file.py b/oauth2client/file.py
index 34a5f48..d20cf6e 100644
--- a/oauth2client/file.py
+++ b/oauth2client/file.py
@@ -22,18 +22,7 @@
 
 import threading
 
-
-try:  # pragma: no cover
-  import simplejson
-except ImportError:  # pragma: no cover
-  try:
-    # Try to import from django, should work on App Engine
-    from django.utils import simplejson
-  except ImportError:
-    # Should work for Python2.6 and higher.
-    import json as simplejson
-
-
+from anyjson import simplejson
 from client import Storage as BaseStorage
 from client import Credentials