[v3] update libtool_VERSION

[Benjamin Kosnik]

> >> Shouldn't that be 7:0:1?
> >
> > No, that would change SONAME to 7,
> 
> No, it doesn't.

Whoops, sorry. You are right.

> > and indicate an incompatible change. I'm just bumping the minor,
> > compatible version.
> 
> See (libtool)Libtool versioning.  You are changeing the interface, so
> CURRENT should be incremented.

Well, just adding interfaces (what is going on here) means increment
age according to your link, which is what this patch did. This is
consistent with existing practice back to 3.4.0...

-benjamin