Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Improve bsdpatch usability:

- Ask only once for "Apply anyway". [1]
- Tell user what file have failed patch rather than just how
many hunks failed.

Reported by: jmg via pfg [1]
Tested by: pfg [1]
Approved by: re (gjb)

Fix file selection logic for the RCS/SCCS case, as was done for the simple
file case before. Bump version because of the changed behavior, which now
matches the documentation.

Reviewed by: pfg

Revert r250972 to fix build.

The error handling for writes to the target file could lead to the final
fclose() being skipped. Fix this by using boolean "&" and "|" instead of
short-cut operators "&&" and "||".
While here, increment the last part of the version string. The reason is
the fixed output file selection logic in pch.c, which was committed as
r250943, yesterday.

Reviewed by: pfg

patch: Follow original versioning convention.

According to the README file [1] the 12u variant, unlike
the 12g variant, contains no copyleft code. It is therefore
convenient to keep using the original versioning scheme to
prevent confusions.

[1] http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/patch/README

- Refresh code with latest OpenBSD revisions.
- Remove $DragonFly$ tags as they are using git nowadays and VCS tags will
not help merging.
- Other changes to Copyright headers to make them consistent with other
source code, we intend to fork from this point.

Reviewed by: pfg

- Add a BSD-licensed patch, ported by Pedro F. Giffuni (pfg) from
DragonflyBSD and install it as bsdpatch. WITH_BSD_PATCH makes it
default and installs GNU patch as gnupatch.

Submitted by: pfg
Obtained from: The DragonflyBSD Project