Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

-v must have a space between it and the variable.

Submitted by: David Wolfskill <david@catwhisker.org>
(did I mention he should be a committer? :-) )

Added section and entry annotations.

Fix dependencies for regex.texi. It is constructed by merging a C header
file with an info source file.

Add infopage installation

GNU Regex 0.12