Pack internals have been significantly refactored, including significant low-level API changes.

As a consequence of this, Dulwich now reuses pack deltas when communicating with remote servers, which brings a big boost to network performance. (@jelmer)

Add 'pack-refs' command. (@danchr)

Handle more errors when trying to read a ref (@danchr )

Allow for reuse of existing deltas while creating pack files (@stspdotname )

cli: fix argument parsing for pack-objects --stdout (@stspdotname)

cli: open pack-objects output files in binary mode to avoid write() error (@stspdotname)

Bump minimum python version to 3.7. (@jelmer)

honor no_proxy environment variable (#1098, @afaul )

In HTTP Git Client, allow missing Content-Type. (@jelmer)

Fix --pure builds (@jelmer, #1093)

Allow passing abbrev to describe (#1084, @nanonyme )