Terminfo often lies about key_backspace and libtickit believes it

[Paul "LeoNerd" Evans]

((this is actually a libtermkey bug but given the pending merge to libtickit, I'll write about it here))

Most terminfo databases lie about the backspace key, claiming key_backspace=\010 (i.e. ASCII BS, 0x08) even though the observed behaviour of the Backspace key is to send \177 (ASCII DEL, 0x7F). What to do about this is unclear.

One possible workaround may be steal vim's idea of asking termios instead, querying the "ERASE" vchar byte and using that for the backspace sequence. It probably works, but it seems an odd way to go about it.