Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

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

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

Fix warnings and set WARNS to 6.

MFC after: 1 week

add cfi test tool

Sponsored by: Carlson Wireless
Reviewed by: imp, Chris Andreson