Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix bsdbox builds after the recent libkvm requirement for libelf.

Fix warning about redefined *_crunchdir_hostname target after r289734.

'hostname' was in the build list twice.

X-MFC-With: r289734
MFC after: 2 weeks
Reported by: sbruno
Sponsored by: EMC / Isilon Storage Division

Add mv / expr ; these are used by the updated freebsd-wifi-build environment.

Do a bunch of fixing and refactoring.

Fix up gzip to crunch right.

Add kenv, although I'm not yet sure why it isn't working on my MIPS
boards (reading kenv always returns blank.)

Import the first cut of "bsdbox".

This uses the existing crunchgen infrastructure to build
a series of tools designed to replace the base and networking
tools on an embedded system.

It reuses 'bsd.crunchgen.mk' to drive the actual file
creation. The rescue build system also uses this.

Unlike busybox, it doesn't include its own source - instead,
it just builds from the sources in /usr/src/ and leverages
the existing BSD framework.

Thie is still quite messy and could do with a whole lot of
cleaning up. However it is proving to be very useful with
my current build framework, allowing me to build binary root
images that are about 30% less than simply cherrypicking files
and libraries from an installworld.