bug#28182: maybe implement CTRL++ to zoom text

[Drew Adams]

> DA> They are free, but there is no reason to waste them.
> 
> Saving them for some future better commands despite many programs
> having already reached a consensus on what they should do?

"Many programs" are not Emacs.  Most programs do not use anywhere
near the number of key bindings Emacs uses (out of the box).
Binding keys by default is not something to do lightly.

"Many programs" use CUA keys too.  Emacs does not, except by user
opt-in (`cua-mode').  That's the right approach, IMO.

> DA> Leaving these commands on the C-x prefix makes sense.  When the
> DA> last key is repeated the action is repeated, which is very quick.
> 
> All I know is please keep C-x C-= runs the command text-scale-adjust
> and add C-= also runs the command text-scale-adjust...

Yes to keeping C-x C-= as text-scale-adjust.
No, C-= does not current run text-scale-adjust; it is unbound.