[9front] program to bind/rebind keys

[binary cat <dogedoge61@gmail.com>]

The program would operate by opening /dev/kbd, then binding its output
to /dev/kbd.
It would read a list of keybindings (from a file and/or command line options),
then operate in a loop of reading a key from (the old) /dev/kbd, checking if it
matches any of the bindings given to it. If it finds a match, it executes the
action associated with it. Otherwise, it passes the keypress on.

This could be used for global keyboard shortcuts by wrapping around rio,
or for per-program keyboard shortcuts.

`awk` is surprisingly close to working for this, but it has a few problems,
both with reading input delimited by NUL instead of LF, and with
non-printable characters in regular expressions.

I'm up to provide a bounty for this, although first I'd like to have a rough
idea of how difficult it would be to either write such a program, or to
fix the problems with `awk`, so I know how much a reasonable bounty
would be.

-- binarycat