- Add Python 3.13 support.
- Alignment.append_sequence() now adds a gap with every chain break by
default. This makes it easier to construct multiple-sequence alignments.
The old behavior can be requested using the new zero_width_break
argument.
- Bugfix: Model.get_deletions() no longer erroneously reports a gap
aligned with another gap as a deletion.
- Bugfix: don't put non-UTF8 computer names in the log file on Windows.