Unicode/EBCDIC

Attached are two patches (one of which, I'm sorry to say, I accidentally
reversed) which start to sanitize Unicode support on EBCDIC. This slightly
affects ASCII users too, but it shouldn't be noticable - I've modified the
behaviour of vx.y.z so that it *always* produces a Unicode-encoded string, and
x.y.z are regarded as Unicode codepoints, even on EBCDIC. (v5.7.0 is NOT
chr(5).chr(7).chr(0) on EBCDIC) Similarly, the %v format modifier for sprintf
now returns Unicode codepoints, even on EBCDIC, for symmetry. (and to make the
$^V test in configpm work - remember that failing, Peter?)

I'll provide a more detailed explanation of what I've done when I get home,
but I'd like MVS people to play with this and see if it makes sense for them.

This wouldn't have been possible without the help of Morgan Stanley Dean
Witter, who gave me access to one of their mainframes for the day.

-- 
Feed me on TOASTIES! There's no HALL for PHILOSOPHERS ON FRIDAYS.
    - Henry Braun is Oxford Zippy

• Unicode/EBCDIC by Simon Cozens