Log Message:
Update to 1.22:

version 1.22 - Sergey Poznyakoff, 2009-03-05

* Support for xz compression

Tar uses xz for compression if one of the following conditions is met:

 1. The option --xz or -J (see below) is used.
 2. The xz binary is set as compressor using --use-compress-program option.
 3. The file name of the archive being created ends in `.xz' and
 auto-compress option (-a) is used.

Xz is used for decompression if one of the following conditions is met:

 1. The option --xz or -J is used.
 2. The xz binary is set as compressor using --use-compress-program option.
 3. The file is recognized as xz compressed stream data.

* Short option -J reassigned as a short equivalent of --xz

* New option -I

The -I option is assigned as a short equivalent for
--use-compress-program.

* The --no-recursive option works in incremental mode.

version 1.21 - Sergey Poznyakoff, 2008-12-27

* New short option -J

A shortcut for --lzma.

* New option --lzop

* New option --no-auto-compress

Cancels the effect of previous --auto-compress (-a) option.

* New option --no-null

Cancels the effect of previous --null option.

* Compressed format recognition

If tar is unable to determine archive compression format, it falls
back to using archive suffix to determine it.

* VCS support.

Using --exclude-vcs handles also files used internally by Bazaar,
Mercurial and Darcs.

* Transformation scope flags

Name transformation expressions understand additional flags that
control type of archive members affected by them.  The flags are:

 - r
   Apply transformation to regular archive members.

 - s
   Apply transformation to symbolic link targets.

 - h
   Apply transformation to hard link targets.

Corresponding upper-case letters negate the meaning, so that
`H' means ``do not apply transformation to hard link targets.''

The scope flags are listed in the third part of an `s' expression,
e.g.:

   tar --transform 's|^|/usr/local/|S'

Default is `rsh', which means that transformations are applied to
both regular archive members and to the targets of symbolic and hard
links.  If several transform expressions are used, the default flags
can be changed using `flags=' statement before the expressions, e.g.:

   tar --transform 'flags=S;s|^|/usr/local/|S'

* Bugfixes

** The --null option disabled handling of tar options in list files.  This
is fixed.
** Fixed record size autodetection.  If detected record size differs from
the expected value (either default, or set on the command line), tar
always prints a warning if verbosity level is set to 1 or greater,
i.e. if either -t or -v option is given.