OS-2532 agent crash because kstat read returned ENOMEM
OS-2531 zfs/zone IO throttle comment improvement and code cleanup
OS-2356 mdb should support embedded dmods in core dumps (backout, needs work)
OS-2305 Would like a way to add-or-update an attr in zonecfg (remove -f?)
4168 ztest assertion failure in dbuf_undirty
4169 verbatim import causes zdb to segfault
4170 zhack leaves pool in ACTIVE state
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>
	[illumos-gate merge]

commit 7fdd916c474ea52896c671bbe7b56ba34a1ca132
    4168 ztest assertion failure in dbuf_undirty
    4169 verbatim import causes zdb to segfault
    4170 zhack leaves pool in ACTIVE state
Merge branch 'master' of git://github.com/joyent/illumos-joyent into smartos/ec