The dependency on po4a is optional. It's never required to install
the translated man pages when xz is built from a release tarball.
If po4a is missing when building from xz.git, the translated man
pages won't be generated but otherwise the build will work normally.
The translations are only updated automatically by autogen.sh and
by "make mydist". This makes it easy to keep po4a as an optional
dependency and ensures that I won't forget to put updated
translations to a release tarball.
The translated man pages aren't installed if --disable-nls is used.
The installation of translated man pages abuses Automake internals
by calling "install-man" with redefined dist_man_MANS and man_MANS.
This makes the hairy script code slightly less hairy. If it breaks
some day, this code needs to be fixed; don't blame Automake developers.
Also, this adds more quotes to the existing shell script code in
the Makefile.am "-hook"s.
use AC_PROG_SED. We don't do anything fancy with sed,
so this should work OK. libtool 2.2 sets SED but 1.5
doesn't, so $(SED) happened to work when using libtool 2.2.
the latest versions found from gzip CVS repository.
configure will try to find a POSIX shell to be used by
the scripts. This should ease portability on systems
which have pre-POSIX /bin/sh.
xzgrep and xzdiff support .xz, .lzma, .gz, and .bz2 files.
xzmore and xzless support only .xz and .lzma files.
The name of the xz executable used in these scripts is
now correct even if --program-transform-name has been used.
This adds lzdiff, lzgrep, and lzmore to the list of symlinks to install.
It also installs symlinks for the manual pages and removes the new
symlinks on uninstall.