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

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

fix the kernel files to match our standard "option<space><tab>" format
such that when commenting/uncommentting lines, horizontal spacing is
maintained...

Also fix some minor comment formatting to line things up, etc...

Reviewed by: gnn, imp
MFC after: 1 week

Strip trailing whitespace.

The GUMSTIX-QEMU config file is almost identical to the GUMSTIX config,
include the latter file from the former rather than duplicating it.

- Add kernel config file for QEMU-emulated gumstix board.