Ufodiff

- bug fix for commit SHA1 digest parsing on Windows
- refactored DeltaFilePathDict class

- bug fix for Python 3 string comparison issue in ufodiff.utilities.ufo module

- PyPI documentation update

- added `deltamd` subcommand to support output of Markdown formatted delta file reports
- added short SHA1 digests for the commit history under analysis
- Commit SHA1 digests added to `delta` subcommand as header of standard output string
- Commit SHA1 digests added to `deltajson` subcommand JSON string with key `commits`

- initial release with support for the following subcommands:
- `ufodiff delta all`
- `ufodiff deltajson all`