range-check the incoming values.

- Simplified some of the ge/set calling sequences.
- Got rid of SMB_ACL_PERMSET_T.

functions.

backup directory if the open of the dest file fails.

the --whole-file and/or --read-batch options are specified.

inplace backup file.

when the kept entry is also a dir.

with a trailing slash.

- Improved the code that tries to avoid scanning the same dir
  twice in a row to not drop any relnamecache entries.

properly even in inc_recurse mode.  Got rid of double output, weird
output order, and outputting of implied dirs w/--no-implied-dirs.

work right.

just in case we end up talking protocol 30 in inc_recurse mode.

sends us a normal sequence of dirs, and we just skip the implied
ones.

sequence of directories in the hierarchy, and works properly when
merging things from multiple sources.

- Fixed name of PTR_EXTRA_CNT (was PTR_EXTRA_LEN).
- Added F_DIR_RELS_P() to support --relative in inc_recurse mode.