Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Add strndup(3) prototype to string.h.

This change was erronously ommitted from the r185690, and attempt
to simply add the prototype to string.h has revealed that several
contributed programs defined local prototypes for strndup(), controlled
by autoconfed config.h. So, manually change #undef HAVE_STRNDUP to
#define HAVE_STRNDUP 1. Next import of the corresponding program would
regenerate config.h, overriding the changes in this commit.

No objections from: kan

Go back to fondling FILE internals.

Unbreak build: gnu sort has been configured to grope inside struct
__sFILE. It's opaque now, so add a function that returns the pending
output bytes.

Pointy hat: jhb

Update version strings to better reflect reality.

Update build infrastructure for sort from GNU coreutils 5.2.1.

Upgrade to textutils 2.1 sort

We HAVE_STPCPY now.

Activate new GNU sort from contrib

Revive GNU sort