Autoconf 2.68 is more picky about correct macro usage and thus I fixed
some wrong call conventions for AC_LANG_PROGRAM. Also factored an m4
conditional construct out from AC_INIT to avoid the "not a literal"
warning.
(min_automake_version): New.
* LINGUAS: Added all languages we supported in 1.2.5.
Copied all po files from 1.2.5.
* autogen.sh: Updated to the modern version, grepping the required
tool versions from configure.ac.