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

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

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.

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

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

$Id$ -> $FreeBSD$

Fixed missing libraries in DPADD.

DPDADD -> DPADD

bmake framework for contrib_amd