fix(parity): rsync bwlimit units, --info categories, --ignore-errors deletion semantics

- --bwlimit: faithful port of rsync 3.4.1 parse_size_arg (default KiB/s,
  binary K/M/G/T/P, decimal KB/MB, KiB/MiB, decimals, 0 = unlimited, 512-byte
  floor, (size+512)/1024 quantization).  Unit tests + docs.
- --info: wire del/remove/name/flist/nonreg/progress to real FastSync events in
  rsync's line format (deleting PATH, sender removed NAME, name lines,
  'sending incremental file list', skipping non-regular file "NAME"); name no
  longer aliases copy; --info=progress drives the progress path and report_stats.
- --ignore-errors: match rsync's default -- a source I/O error skips deletion
  unless --ignore-errors, while the readable tree still transfers and the run
  exits 23.  Covers all delete timings and both send paths.

src/client/usage.c

@@ -243,7 +243,9 @@ void print_usage(void) {
   printf("                      reusable digest is sent (keep the file mode 0600)\n");
   printf("  --no-motd           Suppress display of the daemon's MOTD (the server\n");
   printf("                      still sends it; the client just does not show it)\n");
-  printf("  --bwlimit <KB/s>    Bandwidth limit in kilobytes per second\n");
+  printf("  --bwlimit=RATE      Limit socket I/O bandwidth (default unit KiB/s,\n");
+  printf("                      rsync-style: 0 = no limit; K/M/G/T/P suffixes are\n");
+  printf("                      binary, KB/MB decimal, KiB/MiB binary; decimals allowed)\n");
   printf("  --tls               Enable TLS encryption\n");
   printf("  --cert <path>       TLS certificate file (PEM)\n");
   printf("  --key <path>        TLS private key file (PEM)\n");