Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Reimplementation of world/kernel build options. For details, see:

http://lists.freebsd.org/pipermail/freebsd-current/2006-March/061725.html

The src.conf(5) manpage is to follow in a few days.

Brought to you by: imp, jhb, kris, phk, ru (all bugs are mine)

Add knob NO_NIS (fka NO_YP_LIBC) and make world compileable when set.
If turned on no NIS support and related programs will be built.

Lost parts rediscovered by: Danny Braniss <danny at cs.huji.ac.il>
PR: bin/68303
No objections: des, gshapiro, nectar
Reviewed by: ru
Approved by: rwatson (mentor)
MFC after: 2 weeks

Stop "make depend" from attempting to delete non-existent .depend.

I was missing the HOST_OS_VERSION setting in the fall-back case.
Also, the script was too position dependant. We now have make(1) pass in
the file to grub around in to get our settings from.

Use the native mount and nfs_prot headers.
Also generate nfs_prot_x.c in ANSI-C mode.

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.

Added missing dependancy.

Submitted by: bde
Approved by: obrien

Properly fix the world breakage.

Unpollute the Makefile.inc's abuse of SRCS variable, and move
the generation of header files into include/ subdirecory.

Reviewed by: buildworld

$Id$ -> $FreeBSD$

bmake framework for contrib_amd