3993 zpool(1M) and zfs(1M) should support -p for "list" and "get"
4700 "zpool get" doesn't support -H or -o options
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>