* configure.in (AC_PROG_RANLIB): No longer required as we now use

* configure.in (AC_PROG_RANLIB):  No longer required as we now use
AC_CHECK_TOOL in AC_LIBTOOL_SETUP.
* libtool.m4 (AC_PROG_LIBTOOL):  Pass the $build variable to
ltconfig.
(AC_PROG_RANLIB): replaced with AC_CHECK_TOOL.
* ltconfig.in (build): new variable to hold the build triplet
which is now checked for unless --no-verify is specified.
(--build): new argument to set the build triplet.
(ranlib): Prefer ${host_alias}-ranlib[.exe] if $build is different
to $host.
* doc/libtool.texi (Invoking ltconfig): Document --build option.
* NEWS: Note --build option.