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

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

- Follow the lead of dcphy(4) and pnphy(4) and move the reminder of the PHY
drivers that only ever attach to a particular MAC driver, i.e. inphy(4),
ruephy(4) and xlphy(4), to the directory where the respective MAC driver
lives and only compile it into the kernel when the latter is also there,
also removing it from miibus.ko and moving it into the module of the
respective MAC driver.
- While at it, rename exphy.c, which comes from NetBSD where the MAC driver
it corresponds to also is named ex(4) instead of xl(4) but that in FreeBSD
actually identifies itself as xlphy(4), and its function names accordingly
for consistency.
- Additionally while at it, fix some minor style issues like whitespace
in the register headers and add multi-inclusion protection to inphyreg.h.

Remove bridge(4) from the tree. if_bridge(4) is a full functional
replacement and has additional features which make it superior.

Discussed on: -arch
Reviewed by: thompsa
X-MFC-after: never (RELENG_6 as transition period)

vlan.h is obsolete, don't create it anymore.

Unconditinally turn on VLAN support when building fxp as a module, since
it may be plugged into a kernel that supports VLANs. If the kernel is
not VLAN aware, things will still work as before.

Modules don't really have option support, so this is somewhat of a hack.

Update makefile to reflect vlan support.

Back out 'KMODDEPS = miibus' addition in last commit. This isn't used.

Adjust the fxp module to use the correct directory path, and add a
dependency on miibus.

Use a consistent style and one much closer to the rest of /usr/src

Use .include <bsd.kmod.mk> to get to ../../*/conf/kmod.mk instead of
encoding the relative path.

Pull in sys/conf/kmod.mk, rather than /usr/share/mk/bsd.kmod.mk.
This means that the kernel can be totally self contained now and is not
dependent on the last buildworld to update /usr/share/mk. This might
also make it easier to build 5.x kernels on 4.0 boxes etc, assuming
gensetdefs and config(8) are updated.

Add ${DEBUG_FLAGS} to CFLAGS in bsd.kmod.mk, not in scattered module
makefiles. Bad examples in fxp/Makefile keep getting copied to new
makefiles.

Removed special rules for building and cleaning device interface files
and empty options files. The rules are now generated automatically in
bsd.kmod.mk. Cleaned up related things ($S and ${CLEANFILES}).

Zap some unused echo "#define NFOO 1" > foo.h style defunct stuff.

Don't generate 'bpf.h' since it's not used.

Change the name of the installed KLM to contain a leading "if_".
Except for miibus which is now installed as miibus.ko.

Discussed by: msmith, peter, and wpaul

$Id$ -> $FreeBSD$

Rename bpfilter to bpf.

Use perl, not perl5 to compile interfaces.

Add a sample loadable pci driver Makefile..