- 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

The last big commit: let usr.sbin/ use WARNS=6 by default.

In verbose mode print disk sizes in human readable form as well.

OK'ed by: phk

Make WARNS=5 clean.

Prodded by: Stefan Farfeleder <stefan@fafoe.narf.at>

Diskinfo is a small program to access the basic properties of a disk device:
sectorsize, mediasize etc.

It also contains a small and naïve benchmark which reports on seek
and transfer performance.