* configure.in
(LIBGUILE_INTERFACE_CURRENT): use libtool versioning scheme.
(LIBGUILE_INTERFACE_REVISION): use libtool versioning scheme.
(LIBGUILE_INTERFACE_AGE): use libtool versioning scheme.
(LIBGUILE_INTERFACE): use libtool versioning scheme.
(LIBGUILEQTHREADS_INTERFACE_CURRENT): use libtool versioning scheme.
(LIBGUILEQTHREADS_INTERFACE_REVISION): use libtool versioning scheme.
(LIBGUILEQTHREADS_INTERFACE_AGE): use libtool versioning scheme.
(LIBGUILEQTHREADS_INTERFACE): use libtool versioning scheme.