delta-find: move pre-filtering with other pre-filtering logic This is more consistent and will help use to be in a clean state before dealing with the "too large group" issue. As a side effect, the debug output now skip some useless cases, making it more useful.

delta-find: expand a function definition and call before extendin it This make the next changeset more compact.

debug: add an option to display statistic about a unbundling operation This will helps a lot to understand how the bundling decision have actually impacted pull/unbundle on the other side.

debug: add an option to display statistic about a bundling operation This will helps a lot to understand how the bundling decision might impact pull/unbundle on the other side.

delta-find: add debug information about reuse of cached data This will help us to understand the behavior of find-delta during a pull.

cffi: fix a bytes vs str issue on macOS when listing directories This code hasn't been touched in recent years, and the other implementation return bytes for the filename, so I assume this is a holdover from the py2 days. I was unable to test it on mac though, because the `_osutil` import failed.

packaging: refresh dependency hashes (issue6750) Also, add some documentation to the `.in` files.

matcher: do not prepend '.*' to pattern using ^ after flags Since the previous commit (fixing wider issue), the code generated strange regex. This is now fixed and tested.