- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

A number of places in the source tree still reference cuad.* after
sio(4) was deprecated by uart(4).

s/cuad/cuau/g/

PR: docs/171533
Reviewed by: imp
Approved by: cperciva (implicit)
MFC after: 3 weeks

Start the dreaded NOFOO -> NO_FOO conversion.

OK'ed by: core

Catch up with PHK's sio(4) cuaa->cuad rework [sys/dev/sio/sio.c rev. 1.456].

For variables that are only checked with defined(), don't provide
any fake value.

Add a small program to test/measure with the RFC 2783 API for timing
external signals.