Set a stricter default set of USE-flags
Set a stricter default set of USE-flags

This deviates from the default profile use flags mainly because
we don't need half of it.

It additionally allows us to build a minimal busybox image where
glibc can get decoupled from.

gdm/gentoo-bb,berney/gentoo-bb,edannenberg/kubler,jonasjonas/gentoo-bb,berney/gentoo-bb,edannenberg/gentoo-bb,guruvan/gentoo-bb,edannenberg/gentoo-bb,guruvan/gentoo-bb,jonasjonas/gentoo-bb,gdm/gentoo-bb