* kill devel/libtool and move to devel/libtool13, upgrading to 1.3.5
* upgrade repo-copied devel/libtool14 to 1.4.3
* break out libltdl into its own separate port
* move to version-numbered binaries/scripts (ie: there is *no* 'libtool'
any more -- USE_LIBTOOL and USE_LIBTOOL_VER are your friends)
Approved by: portmgr (kris) - for the bsd.port.mk hooks
Tested by: bento 4-exp builds (repeatedly)