sys/*/conf: do not use "../../conf/" when including std.*

Since config(8) searches sys/conf by default, there's no need to specify
the full relative path here; replace it by the filename alone.

Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/1124

sys: Remove $FreeBSD$: one-line sh pattern

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

sys/*/conf/*, docs: fix links to handbook

While here, fix all links to older en_US.ISO8859-1 documentation
in the src/ tree.

PR: 255026
Reported by: Michael Büker <freebsd@michael-bueker.de>
Reviewed by: dbaio
Approved by: blackend (mentor), re (gjb)
MFC after: 10 days
Differential Revision: https://reviews.freebsd.org/D30265

Split out the NODEBUG options to a common file

This is the superset of the nooptions found in the -DEBUG kernels.

Reviewed by: emaste, manu
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D28152

Set MALLOC_DEBUG_MAXZONES=1 in GENERIC-NODEBUG configurations.

The purpose of this option is to make it easier to track down memory
corruption bugs by reducing the number of malloc(9) types that might
have recently been associated with a given chunk of memory. However, it
increases fragmentation and is disabled in release kernels.

MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation

Update several more URLs

- Primarily http -> https
- Primarily FreeBSD project URLs

This configuration file removes several debugging options, including
WITNESS and INVARIANTS checking, which are known to have significant
performance impact on running systems. When benchmarking new features
this kernel should be used instead of the standard GENERIC.
This kernel configuration should never appear outside of the HEAD
of the FreeBSD tree.