* configure.ac (AC_PREREQ): Require Autoconf 2.58.
(AC_CONFIG_MACRO_DIR): Specify m4 macro directory.
(IT_PROG_INTLTOOL): Replace obsolete AC_PROG_INTLTOOL().  Require
at least intltool 0.35 for full po/LINGUAS and po/Makevars support.
(ALL_LINGUAS): No longer set this environment variable, but rely
on po/LINGUAS support.  Get rid of the CONFIG_STATUS_DEPENDENCIES
substitution hack.
(GETTEXT_PACKAGE): Move the variable assignment to AC_SUBST().

* po/Makevars: Reintroduce this file, as it is finally properly
supported by intltool.  Set XGETTEXT_OPTIONS to the list of
keywords xgettext should recognize.

* autogen.sh: Get rid of the hack that appends XGETTEXT_KEYWORDS
to po/Makefile.in.in.  Also change the invocation order of the
various setup tools according to the recommendation found in the
gettext manual.  Delete some more cruft from the m4/ directory.

* ABOUT-NLS: Get rid of this both large and largely useless file.
Probably a left-over from the time before glib-gettextize.

svn path=/trunk/; revision=581