Remove $FreeBSD$: one-line sh pattern

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

tests/sys/cddl: correctly quote atf_set "require.progs"

The argument has to be a single whitespace-separate value. While touching
all these lines also add ksh93, since `atf_set "require.progs"` overrides
the default value specified in the Kyuafile. This then results in tests
being executed despite ksh93 not being installed.

Reviewed By: asomers
Differential Revision: https://reviews.freebsd.org/D29066

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