stty erase '^?' in v7

[Noel Chiappa]

    > From: Will Senn

    > I didn't know that the delete key served a purpose, interrupt

At MIT, the PWB1 (effectively) system that was standard at Tech Sq had had its
teletype driver completely re-written by the time I started using it, and that
was changed, so I never saw this IRL.

Recently, I needed a Unix to run under Ersatz-11, to talk to physical QBUS
-11's and download them over their console line, so I went with V6 (since I
had not at that point managed to recover the MIT system). Wow. Talk about
a rude awakening!

That was one of the things that was, ah, problematic - and in V6, there's no
way to change the interrupt character. (And no, I didn't feel like switching
to a later version!)

An even bigger problem was that in vanilla V6, there's _no way_ to do 8-bit
input _and_ output. Sheesh. I managed to fix that too, after a certain amount
of pain. (I missed a code path, or something like that, and it took me quite a
while to figure out why my fixes didn't work.)

    Noel