Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

Let the nv.h and dnv.h includes be only in sys directory.

Change consumers to include those files from sys.
Add duplicated files to ObsoleteFiles.

Approved by: pjd (mentor)

Integrate lib/libnv into the build/kyua

Rename all of the TAP test applications from <test> to <test>_test
to match the convention described in the TestSuite wiki page

Phabric: D538
Approved by: jmmv (mentor)
Sponsored by: EMC / Isilon Storage Division