bug#21634: [External] : bug#21634: text-scale-adjust suggestion

[Drew Adams]

> Another command that could use it as well is 'indent-rigidly'.
> Currently it's too inconvenient to type C-g to get out of it.
> Exiting after a delay would be a better option.

Not that I care much about this particular fiddling,
but IMHO, `C-g' to "get out of" what is essentially
a modal, or near-modal interaction, is emacsy and
makes perfect sense.  Having a time-out "get out of"
such contexts seems to me quite wrong & unfriendly.

(Again though, not much concern on my part, for
quitting this command's repeating behavior.)

Timers do things silently, at moments users are
often not aware of.  And users certainly don't want
to _wait_ for a timer as the way to initiate or
terminate some action.  At a minimum there should
be a way to quit on demand (i.e. do it now!).