will be sending 0x7f (DEL) when the backspace key is struck: SWAP_DELETE
For example, xterm sends 0x7f when backspace and hit and an ANSI escape
sequence when the DEL key is hit.

I don't yet have a way to *enable* this setting.

Also, allow the user's setting of NO_EXASCII to take effect even when
auto-terminal type detection is used (yes, the user's terminal can support
ANSI and *not* CP437).