8ddf7784

[YONETANI Tomokazu]

Hi.
The commit 8ddf7784 reverted d9795ca13, and says that C-a ^H works
without it, but it doesn't, at least on Mac OS X and CentOS 4.6,
connected from PuTTY and Terminal.app.  C-a C-BS still works on 8ddf7784,
but I'm not very happy with it (I'd rather use C-a C-p).
On pre-8ddf7784 screen both C-a ^H and C-a C-BS works.  I have no
idea what 'back-tab' is which is said to be broken, but we need to
find a way to fix both :)

Cheers.