usr.sbin: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

iovctl: Fix typos

Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/653

Clean up repeated "All rights reserved"

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)

Add functions for parsing the iovctl config file

Add two functions for parsing the iovctl config file. The config
file is parsed using libucl[1], which accepts most YAML files and
a superset of JSON. The first function is an ad-hoc parser that
searches the file for the PF.DEVICE configuration value. We need
to know that value in order to fetch the schema from the kernel,
and we need the schema in order to be able to fully parse the file.

The second function parses the config file and validates it
against a schema. This function will exit with an error message
if any validation error occurs. If it succeeds, the configuration
is returned as an nvlist suitable for passing to the kernel.

[1] https://github.com/vstakhov/libucl

Differential Revision: https://reviews.freebsd.org/D86
Reviewed by: jhb
MFC after: 1 month
Sponsored by: Sandvine Inc.