Changes

Summary

1. merged
2. avoid noise via context.progress (amending 68162e4f60a7);
3. more robust treatment of rsync on macOS (see also 96fb1f9a4042);
4. tuned whitespace;
5. more robust: no change of directory attributes of initial test, notably target without .hg_sync meta data;
6. merged
7. added lemmas reflp_on_Inf and reflp_on_Sup
8. replaced HOL.implies by Pure.imp in reflp_mono for consistency with other lemmas
9. added lemmas reflp_on_inf, reflp_on_sup, and reflp_on_mono
10. merged
11. more robust: protect_args does not work with rsync 2.x from macOS, and is not required in typical situations;
12. clarified context with global defaults;
13. tuned signature;
14. clarified signature: more explicit type Rsync.Context;
15. clarified signature;
16. clarified modules;
17. provide python-3.10.4 for darwin and linux;
18. provide hugo-0.88.1 for darwin and linux;