Log Message:
Merge DragonFly changes back to the .m4 files as documented in
devel/libtool/patches/manual.README.  Changes:

* don't invent another $version_type when you're just duplicating one
  already in existence (freebsd-elf)

* mark chosen $version_type as a very poor choice; this should be fixed
  to use the libtool-team-supported "linux" type in the future, but will
  cause a binpkg flag day (for DragonFly only) when that happens

PKGREVISION *not* bumped as this is a non-event for all platforms.