Perfact-zodbsync

* Auto-stash unstaged changes if picking commits

* Include a test suite and some first tests

* Allow picking commit ranges by using COMMIT1..COMMIT2

* Switch to using a single excutable `zodbsync` with subcommands like
`record`, `playback`, `watch` and `pick`, opening the way to add further
functionality.

* Remove unused features like recording since a given timestamp or
transaction ID. Also remove `--apply` functionality, which was not very
helpful in the case of merge conflicts. If you really need to apply a
patchfile, use `git am` directly, reset the branch to before the resulting
commit and `pick` it again.

Expose methods to read and write objects as well as obtain the modtime of an
object.

Sort properties alphabetically when recording, ensuring stability when
playing back and re-recording.

Consistently use relative paths and os.path.join, fixing 15.

Change handling of strings in metadata for transition from Python 2 to 3.

* Properties that were stored as bytes in Python 2 and are stored as Unicode
in Python 3 are now recorded using UTF-8 literals instead of their 7-bit
representation ('testü' instead of 'test\\xc3\\xbc'). This allows
transferring the meaning of such strings from Python 2 to 3 rather than the
implementation details, which changed for these properties.

* Titles that were already Unicode in Python 2 are now encoded when
recording, allowing a smaller diff in the transition to Python 3.

* Metadata recording no longer attempts to split long lines.

WARNING: If updating to this version, you must expect a large diff in your
repository on the next call to zoperecord.

Provide a wrapper to apply patches and play back the affected objects.

Fix python3 crash in read_pdata, source might be bytes or string.

Allow playing back of commits from a remote repository.

Fix package naming error when trying to send mail with commit summary.