v200213

This is (probably) going to be the last Python2-only release.

Various fixes and new features:

* Tag maps now uses the same syntax as branch and author maps.

* Fast export now ignores obsolete changesets in the source
  repository, contributed by Dave Townsend.

* Support for native git submodules, contributed by Dave Townsend.

* Various submodule handling fixes by Mokhamed Dakhraui.

* Plugins to overwrite null messages and prefix an issue number with a
  user-defined string, by James Douglass.

* Extended functionality in the branch_name_in_commit plugin, by Chris
  J Billington.

* Print a warning and ignore files which cannot be tracked by git, by
  Chris J Billington.

* Backwards compatible adaptation to Mercurial 5.3, by Matthijs van
  der Burgh.

* Documentation of the default branch behavior, by Justin Murray.

v190913

Various fixes and new features:

* Remove removed submodules (frej#156)
  Contributed by MokhamedDakhraui <mokhamed_93@mail.ru>

* Be more tolerant of non-PEP349 systems (frej#143, frej#160)

* Fix broken Markdown links in README (frej#164)
  Contributed by Jonathan Paugh <jpaugh@gmx.us>

* Allow (in many cases) broken name sanitizer to be disabled (frej#155)

v190107

Changes since v180610

* Fast-export now adheres to PEP 394

* Support for Mercurial >4.7, contributed by Daniel Small

* A plugin system for mangling commit messages and file contents,
  contributed by Johan Henkens

* Support for mercurial subrepos, contributed by Johannes Carlsson

v180610

* Fast-export now requires Mercurial 4.6

* Add a section in the readme about system requirements, researched by
  @rinu and contributed by @gcb.

v180317

From now on all future releases will be signed.