use of with statement breaks Python 2.4 compatibility

[David Carr]

According to the python reference [1], the with statement was introduced in Python 2.5. According to the Dulwich main page [2], Dulwich is intended to be tested with (and presumably, support) CPython 2.X where X >= 4.

The line in question is in dulwich/repo.py:
with open(os.path.join(root, ".git"), 'r') as f:

I've attached an attempt at a patch.

[1]: http://docs.python.org/2/reference/compound_stmts.html#the-with-statement
[2]: http://www.samba.org/~jelmer/dulwich/

[Jelmer Vernooij (jelmer)]

Merged, thanks!