* Correct vfs_vget operator, looking up root, and setting va_name.
* Set correct inode for . and .. in vnop_readdir
* Fix possible vnode ref leak in vget
* Correct nlink for directories
* Correct volname in getattr
* remove disabling of spotlight
Remove legacy memory safety check as pressure checks now work.
Make the reply to getattrlist's ATTR_VOL_CAPABILITIES&VOL_CAP_FMT_CASE_SENSITIVE
to based on ZFS_PROP_CASE setting of file-system.
This allows Adobe's installer from passing the "Installation on case-sensitive
          volumes is not supported. Please choose a different volume for
          installation.
Review showed we are not calling arc_adjust_metadata() and upstream
does not call arc_kmem_reap_now() in KERNEL mode.
Mixing kmem_alloc, with strfree() is a bad idea.
Disable ZFS_DEBUG in dbuf.c, as it has not been fully ported yet, and
panics in zpool create.
Restore missed free-memory-scribble to silence ASSERT in debug build.
Remove calls to kmem_flush(), which do nothing.
Raise default arc_min and enable more tunables
Don't reset arc_meta_max=0 just because arc_max tunable gets set.

Also,
- Correct a comment to say 3/4 instead of 1/4.
- Log changes to the arc_min and arc_meta_limit tunables.
WIP: adjust min arc size. only release as much memory as the OS requests, rather than release 1MB when the OS says zero memory needed.
Add missing calls to arc_kmem_reap_now() - Illumos - flush the ZIO quantum caches when aggressively reducing arc size.
Reduce ARC to 25% until poor performance with larger ARC sizes is understood.
Merge branch 'pk2' of github.com:openzfsonosx/zfs into pk2
Add missing _ to #define KERNEL - this was preventing some code from being compiled.