- 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

Minor mdoc nits.

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Catch up with recent FP-related changes to scanf.3 and vfwscanf.c.

mdoc(7) police: tiny nits.

Approved by: re

Consistently mark std(in|out|err) with .Dv, because that's how they
are marked up in stdio(3), and because they are defined expressions
of type "FILE *".

Approved by: re

mdoc(7) police: markup overhaul.

Approved by: re

Add cross-references between wide character and single-byte character
versions of printf() and scanf().

Add implementations of wscanf() and related functions: fwscanf(), swscanf(),
vfwscanf(), vswscanf(), vwscanf(). As the name suggests, these are wide-
character versions of the scanf() family of functions.