Merge pull request #443 from boegel/fix_ordereddict

import OrderedDict from git.odict rather than directly from collections, to pix Py2.6 compatibility

Author: Byron

git/cmd.py

@@ -13,7 +13,7 @@
 import errno
 import mmap
 
-from collections import OrderedDict
+from git.odict import OrderedDict
 
 from contextlib import contextmanager
 import signal