Remove residual blank line at start of Makefile

This is a residual of the $FreeBSD$ removal.

MFC After: 3 days (though I'll just run the command on the branches)
Sponsored by: Netflix

Remove $FreeBSD$: one-line sh pattern

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

Remove residual blank line at start of Makefile

This is a residual of the $FreeBSD$ removal.

MFC After: 3 days (though I'll just run the command on the branches)
Sponsored by: Netflix

Remove $FreeBSD$: one-line sh pattern

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

IFH@204581

Merge from head at r201628.

# This hasn't been tested, and there are at least three bad commits
# that need to be backed out before the branch will be stable again.

The last big commit: let usr.sbin/ use WARNS=6 by default.

WARNS=6 cleanup. This includes:
- Apply __unused on unused parameters
- Use const where suitable
- Use PRIu64 instead of the deprecated %q
- Bump WARNS to 6

Perform a major cleanup of the usr.sbin Makefiles.
These are not perfectly in agreement with each other style-wise, but they
are orders of orders of magnitude more consistent style-wise than before.

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

Set the default manual section for usr.sbin/ to 8.

Add and activate the man page for memcontrol(8).

Reviewed by: msmith

Commandline tool for manipulating memory range attributes.

Remove residual blank line at start of Makefile

This is a residual of the $FreeBSD$ removal.

MFC After: 3 days (though I'll just run the command on the branches)
Sponsored by: Netflix

Remove $FreeBSD$: one-line sh pattern

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

IFH@204581

Merge from head at r201628.

# This hasn't been tested, and there are at least three bad commits
# that need to be backed out before the branch will be stable again.

The last big commit: let usr.sbin/ use WARNS=6 by default.

WARNS=6 cleanup. This includes:
- Apply __unused on unused parameters
- Use const where suitable
- Use PRIu64 instead of the deprecated %q
- Bump WARNS to 6

Perform a major cleanup of the usr.sbin Makefiles.
These are not perfectly in agreement with each other style-wise, but they
are orders of orders of magnitude more consistent style-wise than before.

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

Set the default manual section for usr.sbin/ to 8.

Add and activate the man page for memcontrol(8).

Reviewed by: msmith

Commandline tool for manipulating memory range attributes.

IFH@204581