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

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

The NetBSD Foundation has granted permission to remove clause 3 and 4 from
their software.

Obtained from: NetBSD

Use the newly brought %U macro.

Improve the description a bit and add a reference to vlan(4).

Update URL.

Don't cross-reference gem(4) and hme(4); maybe this made some sense
back when these two were the only two NIC drivers working on sparc64
but it no longer does nowadays.

MFC after: 3 days

Xref altq(4) for drivers that support it according to altq(4).

Work around an apparent mdoc(7) bug.

Spotted by: marius
Discussed with: ru

Break long lines and kill a few instances of EOL whitespace.

Noticed by: ru

Add a "Load module on start up" comment, similar to mac_*.4 pages[1].
Quote .Cd and .Nd text.
Bump doc date.

Requested by: some user through ru
Supported by: ru, dwmalone, brueffer

- Capitalize Ethernet and Fast Ethernet.
- Add a NOTES section with information regarding the "local-mac-address?"
system configuration variable on sparc64 and add a reference to eeprom(8)
for using it. Dump document date for this.
- In dc.4, add the on-board DM9102A on Sun Netra X1 and Sun Fire V100 to
the list of known working devices.

Assorted markup, spelling, and grammar fixes.

Update URL of the FEPS PDF at sun.com.

- Add manpages for the gem and hme ethernet drivers. These were obtained
from NetBSD, and changed slightly to account for FreeBSD specifics.
- Hook them up to the build.
- Add them to the list of miibus-using drivers in miibus(4).