Define libipf internal library


git-svn-id: svn+ssh://svn.freebsd.org/base/head@275029 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Convert sbin/ to LIBADD
Reduce overlinking


git-svn-id: svn+ssh://svn.freebsd.org/base/head@275030 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f