Log Message:
py-dulwich: updated to 0.19.14

0.19.14:
* Strip superfluous <> around email.
* Stop checking for ref validity client-side. Users can
  still call check_wants manually.
* Switch over to Google-style docstrings.
* Add a ``dulwich.porcelain.active_branch`` function.
* Cleanup new directory if clone fails.
* Expand "~" in global exclude path.