- 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

Move U-Boot compatibility library to WARNS=2 level.

style(9) & style.Makefile(9)

Reviewed by: raj

MFp4 (e500):

Add support for U-Boot. This uses the U-Boot API as developed by
Rafal and which is (will be) part of U-Boot 1.3.2 and later.

Credits to: raj@