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

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

Change the E1000 driver option header handling to match the
ixgbe driver. As it was, when building them as a module INET
and INET6 are not defined. In these drivers it does not cause
a panic, however it does result in different behavior in the
ioctl routine when you are using a module vs static, and I
think the behavior should be the same.

MFC after: 3 days

Change defines in the igb driver to allow an easier selection of
the older if_start/non-multiqueue interface from the stack. This
is not the default, but can be turned on in the Makefile now regardless
of the OS level to allow either testing or use of ALTQ.

MFC after: one week

Sync with Intel internal source:
shared code update and small changes in core required
Add support for new i210/i211 devices
Improve queue calculation based on mac type

MFC after:5 days

Remove unnecessary clean target in em(4), igb(4) and ixgbe(4).
While here also remove man target in igb(4).

Reviewed by: jfv

OK, I was a bit sleep this morning and checked in
the core changes but left out the shared code, lol.
Well, and a couple fixes to the core... hopefully
this will all be complete now.

Happy happy joy joy :)

Updates for both the em and igb drivers, add support
for multiqueue tx, shared code updates, new device
support, and some bug fixes.

Add opt_inet.h which has been needed since r184718, which had
introduced checks for #ifdef INET.

MFC after: 54 days

Change Makefile to reflect new directory structure

MFC after:ASAP

This update primarily addresses the ability to have both the em
and the igb driver static in the kernel. But it also reflects
some other bug fixes in my development stream at Intel.
PR 122373 is also fixed in this code.

Remove option headers that do not exist and are not used
from the Makefiles in sys/modules.
(opt_devfs.h, opt_bdg.h, opt_emu10kx.h and opt_uslcom.h)

Approved by: rwatson (mentor)

This change introduces a split to the Intel E1000 driver, now rather than
just em, there is an igb driver (this follows behavior with our Linux drivers).
All adapters up to the 82575 are supported in em, and new client/desktop support
will continue to be in that adapter.

The igb driver is for new server NICs like the 82575 and its followons.
Advanced features for virtualization and performance will be in this driver.

Also, both drivers now have shared code that is up to the latest we have
released. Some stylistic changes as well.

Enjoy :)