git_handler: use repo.__getitem__ instead of (removed) repo.changectx As stated in https://phab.mercurial-scm.org/D3037, repo.__getitem__ should be used instead of repo.changectx, which was removed.

include COPYING
include MANIFEST.in
include README.md

recursive-include hggit *.py *.rst
recursive-include tests *.t *.py *.py.out hghave latin-1-encoding testutil