Release Notes: 0.3.1

This is a brown paper bag release. It turns out I managed to break the upgrade path only 10 commits before the release.

What's new since 0.3.0?

• git cinnabar fsck doesn't fail to upgrade metadata.
• The remote.$remote.cinnabar-draft config works again.
• Don't fail to clone an empty repository.
• Allow to specify mercurial configuration items in a .git/hgrc file.