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)

Move all remaining tests except for:
make(1): Does not work like the other tests. Its Makefile is
self-testing.
m4(1): It uses complex voodo to test GNU m4(1) features.

To the new framework. I had worried about passing the binary data that
uudecode(1)'s test passes to diff(1) might give a user something nasty,
but this is unlikely to happen as even with an unmodified old nasty
diff(1) which doesn't recognise many binary files, these binary files
are recognised. Using $DIFF instead of `diff' in the library and making
it possible to override this with `cmp -s' might be nice some day, but
as of this second, there's no immediate need.

Start adding framework for userland regression tests, and tests for
uuencode and uudecode.