auditdistd: update for sys/capability.h rename in r263232

Merge OpenBSM 1.2 alpha 4.

MFC after: 2 weeks
Relnotes: yes

Merge OpenBSM 1.2-alpha2 from vendor branch to FreeBSD 10-CURRENT; the
primary new feature is auditdistd.

Obtained from: TrustedBSD Project
Sponsored by: The FreeBSD Foundation (auditdistd)