- 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

Merge gdtoa-20110304.

Import gdtoa sources dated 2011-03-04. This version includes a number
of bugfixes, although I believe we already have local patches for the
ones people are likely to notice.

Per a request from arundel@, I also added the vendor's change log,
which is available separately from ftp://ftp.netlib.org/fp/.