We need not wait for a while any longer after pressing ESC or ^D.
Problem description:
If a user types characters during performing completion (ESC)
or listings (^D), the chars are inserted at weird position of
the command line.
This makes the command line unusable and irritates the user.
I noticed this on 386BSD(98), probably six years ago.
This change fixes the bug by implementing salvage of the characters.
The salvaged chars are added at the end of the command line.
An extra ioctl(FIONREAD) is required to work-around a glitch on
kernel tty driver.
