* libtool.m4: CVS Autoconf guarantees a decent default IFS, so

* libtool.m4: CVS Autoconf guarantees a decent default IFS, so
there is no need for us to preset it anymore.
Be careful not to set IFS="${IFS}$PATH_SEPARATOR" for PATH
splitting, otherwise spaces in directory names will be lost.
Use $PATH_SEPARATOR... don't rely on $ac_path_separator, which was
an autoconf internal until just now, when it disappeared!
* ltmain.in: Default IFS once, at the start.
Reported by Akim Demaille <akim@epita.fr>