Implement changing start revision feature(#62)
Merge pull request #65 from syohex/set-start-revision-feature

Implement changing start revision feature(#62)
Drop Emacs 23 from CI
Bump up version and update Changes
Add git-gutter:set-start-diff description
Improve for backends
Merge pull request #66 from syohex/improve-vcs

Improve for backends
Bump up version and update Changes