bug#11871: "libtoolize -f" does not force links over real files.

[Marko Lindqvist]

We invoke libtoolize with single parameter "-f"; so it is supposed to
force creation of symbolic links. I made tarball ('make dist') to
which real files went instead of would-be-broken-in-target symbolic
links. However, 'make dist' machine having libtool 2.4.2 and target
machine having 2.4 resulted in failure in simple "./configure && make"
so I had to run also libtoolize there. Build failure persistet after
"libtoolize -f", and went away only when I did "libtoolize -fc"


 - ML