tests: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

ZFS: fix the delegate tests

These tests have never worked correctly

* Replace runwattr with sudo
* Fix a scoping bug with the "dtst" variable
* Cleanup user properties created during tests
* Eliminate the checks for refreservation and send support. They will always
be supported.
* Fix verify_fs_snapshot. It seemed to assume that permissions would not yet
be delegated, but that's not how it's actually used.
* Combine verify_fs_promote with verify_vol_promote
* Remove some useless sleeps
* Fix backwards condition in verify_vol_volsize
* Remove some redundant cleanup steps in the tests. cleanup.ksh will handle
everything.
* Disable some parts of the tests that FreeBSD doesn't support:
* Creating snapshots with mkdir
* devices
* shareisci
* sharenfs
* xattr
* zoned

The sharenfs parts could probably be reenabled with more work to remove the
Solarisms.

MFC after: 2 weeks
Sponsored by: Axcient
Differential Revision: https://reviews.freebsd.org/D21898

ZFS test suite: fix uses of illumos /dev/[r]dsk/ and /dev/zvol/[r]dsk/

Add the ZFS test suite

It was originally written by Sun as part of the STF (Solaris test framework).
They open sourced it in OpenSolaris, then HighCloud partially ported it to
FreeBSD, and Spectra Logic finished the port. We also added many testcases,
fixed many broken ones, and converted them all to the ATF framework. We've had
help along the way from avg, araujo, smh, and brd.

By default most of the tests are disabled. Set the disks Kyua variable to
enable them.

Submitted by: asomers, will, justing, ken, brd, avg, araujo, smh
Sponsored by: Spectra Logic Corp, HighCloud