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

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

mxge's tunable hw.mxge.rss_hash_type cannot be set from the
loader, because it uses a reserved suffix (_type). Fix
this by removing the "_" and renaming the tunable to
hw.mxge.rss_hashtype. The old (rss_hash_type) tunable is
still fetched, in case people load the driver via scripts.
When both are present in the kernel environment,
the new value (hw.mxge.rss_hashtype) overrides the old
value.

Approved by: re (kib)

- mention new firmware images used in multi-slice mode
- mention LRO support
- describe multi-slice related tunables.
- correct DIAGNOSTICS section to reflect that missing firmware
is non-fatal.

Submitted by: gallatin

- This driver will first appear in 6.3, not 7.0

MFC after: 0 days

Xref altq(4).

Revise markup.

Mention TSO support.

- new sentence -> new line
- s/freebsd/FreeBSD/ for consistency
- eol and eof whitespace removed

s/MYRI10GE/MXGE/ and a typo fixed.

- Complete the myri10ge -> mxge name change by doing a mechanical
s/myri10ge/mxge/g replacement in the myri10ge files. A few contuation
lines were joined because of the regained columns.
- Hook the mxge driver back to the build.

10GbE mode driver and binary firmware for Myricom's PCI-express NICs.
More info regarding these nics can be found at http://www.myri.com.

Please note that the files
sys/dev/myri10ge/{mcp_gen_header.h,myri10ge_mcp.h} are internally
shared between all our drivers (solaris, macosx, windows, linux, etc).
I'd like to keep these files unchanged, so I can just import newer
versions of them when the firmware API/ABI changes. This means I'm
stuck with some of the crazy-long #define names, and possibly
non-style(9) characteristics of these files.

Many thanks to mlaier for doing firmware(9) just as I
needed it, and to scottl for his helpful review.

Reviewed by: scottl, glebius
Sponsored by: Myricom Inc.