Add non-TRUSTEDBSD prefixed knobs for _PC_ACL* and {CAP,INF,MAC}_PRESENT knobs

It's not necessarily intuitive that the variables to query contain TRUSTEDBSD
in the prefix. Add non-TRUSTEDBSD prefixed knobs for querying things like
"_PC_ACL_NFS4"

MFC after: 1 week
Relnotes: yes
Sponsored by: EMC / Isilon Storage Division

$ getconf TRUSTEDBSD_ACL_NFS4 /poof/
1
$ getconf ACL_NFS4 /poof/
1
$ getconf ACL_NFS4 /
0
$ mount |grep /poof
poof on /poof (zfs, local, nfsv4acls)
$ mount -p |awk '$2 == "/"'
/dev/da0p2 / ufs rw 1 1