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

[Juri Linkov]

>>   > >   > Please tell what is your problem, and why "C-x C-+" doesn't solve 
>> it?
>>   > >
>>   > > Does C-x C-+ increase the font size?
>>
>>   > Yes.  And "C-x C--" decreases it.
>>
>> It would be better to make C-+ do it also
>> since people used to other applications will try that.
>
> Does that make sense even if we don't change the corresponding C--
> binding to decrease the font size?

Rather not because it will violate user expectations that C-- is symmetric.
Now that we have the mouse zooming, the need in additional keys diminished.