Msg2po

Added support for `all_utf8`, `all_utf8_yes_really_all` parameters to `.bgforge.yml`. Use the first one to consider all
files except DOS_FILENAMES in UTF-8, add the second one to consider even DOS_FILENAMES UTF-8.

Fixed file2msgstr invocation.

Fixed unfuzzy not working on Windows due to different default encoding.

Action: upgraded [paths-filter](https://github.com/AurorNZ/paths-filter) to 3.0.1.

- Added missing console entry point for `poify.py`, it can now be called as `poify`.
- Fixed spurious [change messages](https://github.com/BGforgeNet/msg2po/issues/5) for lines that are the same.
- Fixed `dir2msgstr` [missing](https://github.com/BGforgeNet/msg2po/issues/7) new female entries.
- Fixed `poify` to always use [Linux style paths](https://github.com/BGforgeNet/msg2po/issues/4) in occurrences, even on
Windows.
- POlib updated to 1.2.0.

Action: added [handle-charsets](https://github.com/BGforgeNet/handle-charsets) capability.