bug#14704: 24.3.50; cl-lib breaks built-in Emacs version

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Dmitry Gutov <dgutov@yandex.ru>,  lunaryorn@gmail.com,  lekktu@gmail.com, 
>  14704@debbugs.gnu.org
> Date: Mon, 24 Jun 2013 22:35:25 -0400
> 
> > We lack a lot of infrastructure for that, like access from Lisp to
> > data structures manipulated by the display engine.
> 
> For the tty case at least we could image just use the sequence of bytes
> sent to the tty.

True, but even TTY output is to some extent dependent on the terminal
capabilities, so parsing such byte streams is not entirely trivial.