The N_host_libs dance only makes sense if host is FreeBSD.
Even then, if MK_host_egacy is yes we need libmd
libnetbsd does not need libutil when using libegacy
Sponsored by: Juniper Networks, Inc.
Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.
Still need to add real targets under targets/ to build packages.
Differential Revision: D2796
Reviewed by: brooks imp