Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC of the ixgbe driver including the follow revisions:

235547,235964,241616,241646,241856,241885,242403,
242421,243714,243716,243718,243721,243724,243725,
243728,243729,243733,243735,243736,243741,243833,
244514,246128,246482,247035,247056,247822,247823

Note: 246482 includes only the changes in the ixgbe driver
and the buf_ring supporting code in if_var.h and buf_ring.h
igb and em will be seperate commits, and non-Intel drivers
can commit the changes at will.

Reviewed by:rss, jhb

Clean some 'svn:executable' properties in the tree.

Submitted by: Christoph Mallon

While here, merge some other mergeinfo properties that
were left behind from my commits

/head/include:r241008,241141,241181
/head/contrib/gcc:r244776,244792
/head/cddl:r238457,238509,238558

MFC of the ixgbe driver. Including revisions:
228276,229767,229939,230329,
230572,230775,230790,231796,
232238,234137,234229,234620

New hardware support: Intel X540 adapter support added.
Some shared code reorganization along with the new adapter.
Sync changes to OACTIVE in igb into this driver.
Misc small fixes.