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 $FreeBSD$: alt two-line .c pattern

Remove /^\s*__RCSID\("\$FreeBSD\$"\);\n\n/

Fix formatting of the usage() output

Improve unit parsing of mpsutil.

Previously, it used atoi(3) to parse the unit parameter, which would silently
yield a unit of 0 in the presence of an invalid unit number. As most users of
mpsutil(8) are likely to have at least a unit 0, this is could have confusing
results.

This behaviour was particularly unintuitive if one incorrectly passed an
adapter device name, or a device path, instead of a unit number. In addition
to using strtoumax(3) instead of atoi(3) to parse unit numbers, support
stripping a device name (e.g. mps1) or path (e.g. /dev/mps2) to just its unit
number.

Reviewed by: scottl (earlier version)

Regularize the Netflix copyright

Use recent best practices for Copyright form at the top of
the license:
1. Remove all the All Rights Reserved clauses on our stuff. Where we
piggybacked others, use a separate line to make things clear.
2. Use "Netflix, Inc." everywhere.
3. Use a single line for the copyright for grep friendliness.
4. Use date ranges in all places for our stuff.

Approved by: Netflix Legal (who gave me the form), adrian@ (pmc files)

mpsutil: correct style

Reported by: bapt

mpsutil: add missing braces

Obtained from: DragonFly (c5d53f11a9510c5c79e196857a1200925fffacc8)

Add a new 'debug' command tree and 'dump_reqs' command to grab and parse
command and chain frames of in-flight I/O from the driver.

Sponsored by: Netflix

Add copyright for Netflix for the files that changed from mptutil

Make mpsutil open the mpr devices when named mprutil
Make mprutil a hardlink to mpsutil

Sponsored by: Gandi.net

Iniital hack of mpsutil