PAX SEGVGUARD: import new version of segvguard from Danilo

Submitted-by: Danilo Egêa Gondolfo <danilo@freebsd.org>
Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com>
PAX SEGVGUARD: style(9)

Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com>
PAX ASLR/SEGVGUARD: properly name aslr and segvguard status

Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com>