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

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

Use the new bus device_shutdown hook for performing the shutdown action
on the ee16 parts rather than explicitly registering an event handler
that wasn't being torn down on detach.

Make ie(4) MPSAFE:
- Add a mutex to the softc and use it to protect the softc and device.
- Setup the interrupt handler in the common code instead of in each front
end and do it after ether_ifattach().
- Use ie_stop() and ieinit_locked() in iereset() rather than frobbing IFF_UP
and invoking ieioctl().
- Use DELAY() to implement a spin loop on a register with a timeout rather
than scheduling a timeout and then doing a tight spin on the register.
In the non-MPSAFE case this would never have worked because the spinning
code held Giant and the timeout routine would have been blocked on Giant
forever. The same approach would not worke in the MPSAFE case either for
the same reason, hence use a loop around DELAY().
- Clear IFF_DRV_(RUNNING|OACTIVE) in ie_stop() rather than in callers.
- Call ieinit_locked() directly rather than ieioctl(!) from ie_mc_reset().
- Don't leak the rx frame buffer on detach.

Tested by: Thierry Herbelot thierry of herbelot.com

Use if_printf() and if_xname and retire 'unit' from the softc.

Stop embedding struct ifnet at the top of driver softcs. Instead the
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.

This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.

Other changes of note:
- Struct arpcom is no longer referenced in normal interface code.
Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
To enforce this ac_enaddr has been renamed to _ac_enaddr.
- The second argument to ether_ifattach is now always the mac address
from driver private storage rather than sometimes being ac_enaddr.

Reviewed by: sobomax, sam

Don't use pessimal (u_short) types for i/o ports. This is mainly for
completenss. The pessimization is tiny compared with i/o port slowness
except on very old machines, but code that used signed short types for
i/o ports was unpessimized long ago, and the macro that detected it
recently started working for u_short types too. Use of bus space
should have made this moot long ago.

Not tested at runtime by: bde

- Move driver to newbus.
- Provide identify methods for EtherExpress and 3c507 cards; this
means these cards no longer need wired configs.
- Provide a detach method.