bug#21695: 25.0.50; Change most occurrences of `setq' in Emacs manual to `customize-set-variable'? Really?

[Gregory Heytings]

> > Because init files are typically not bytecompiled, and because that 
> > would not catch interactive uses with e.g. M-:.
>
> Both would be most unwelcome here.  I often use `setq' in short "init" 
> files for debugging purposes and sometimes use `setq' via M-: during 
> debugging.  In neither of these cases I wanted to be disturbed by any 
> warnings.  I would, however, welcome being warned when a user option is 
> overridden by a package I load, either by a local binding or `setq'. 
> At compile time.

The point is not to display unnecessary warnings.  The point is only to 
display warnings for custom variables that should not be set with setq 
because they have a :set form, or IOW, to display warnings for custom 
variables that should be set with customize-set-variables.