* Use global umask when creating missing intermediate directories.
* When symlinks are not available, extract symbolic links as hard links.
* Diagnose extraction of contiguous files as regular files.
* New --backup, --suffix and --version-control options.

Various changes
* Better support of huge archives with --tape-length and --totals.
* Rename option --read-full-blocks (-B) to --read-full-records (-B).
* Rename option --block-size (-b) to --blocking-factor (-b).
* Rename option --record-number (-R) to --block-number (-R).
* With --block-number (-R), report null blocks and end of file.
* Implement --record-size for introducing a size in bytes.
* Delete --block-compress option and rather decide it automatically.
* Rename option --modification-time to --touch.

Many bugs are squashed, while others still run free.