Log Message:
0.18.2:
TEST FIXES
 * Use constant timestamp so tests pass in all timezones, not just BST.

0.18.1:
BUG FIXES
 * Fix syntax error in dulwich.contrib.test_swift_smoke.

0.18.0:
BUG FIXES
 * Fix remaining tests on Windows.
 * Fix build of C extensions with Python 3 on Windows.
 * Pass 'mkdir' argument onto Repo.init_bare in Repo.clone.
 * In ``dulwich.porcelain.add``, if no files are specified,
   add from current working directory rather than repository root.
 * Properly deal with submodules in 'porcelain.status'.
 * ``dulwich.porcelain.remove`` now actually removes files from
   disk, not just from the index.
 * Fix handling of "reset" command with markers and without
   "from".
 * Fix handling of "merge" command with markers.
 * Support treeish argument to porcelain.reset(), rather than
   requiring a ref/commit id.
 * Handle race condition when mtime doesn't change between writes/reads.
 * Fix ``dulwich.porcelain.show`` on commits with Python 3.

IMPROVEMENTS
 * Add basic support for reading ignore files in ``dulwich.ignore``.
   ``dulwich.porcelain.add`` and ``dulwich.porcelain.status`` now honor
   ignores.
 * New ``dulwich.porcelain.check_ignore`` command.
 * ``dulwich.porcelain.status`` now supports a ``ignored`` argument.

DOCUMENTATION
 * Clarified docstrings for Client.{send_pack,fetch_pack} implementations.