* configure.ac, NEWS: Version 1.20.90

* configure.ac, NEWS: Version 1.20.90
* doc/tar.texi: Document -J, --no-auto-compress, etc.
* src/buffer.c (ct_tar): New constant.
(magic): Add lzop support.  Proposed by Kevin Day
<thekevinday@gmail.com>.
(check_compressed_archive): Do not use autodetect if the
compression program was specified explicitly.
Fall back to analyzing archive name, if the autodetection fails.
* src/suffix.c: Add .lzo
* src/tar.c: New options --lzop and --no-auto-compress.
New short option -J (alias for --lzma).