bug#6755: 24.0.50; Customize buffer is too wide. Put doc string on separate line.

[Drew Adams]

> I've tried this with a few `choice' defcustoms, but they all displayed
> properly.  And the one you included in the screenshots is not 
> available in Emacs 24, so I can't reproduce the bug.
> 
> Do you have an example that shows this behaviour for a defcustom in
> Emacs 24?

Yes, the same example.  Here is the defcustom:

(defcustom icicle-incremental-completion-flag t
  "..."
  :type 
  '(choice
    (const 
     :tag
     "Do not update `*Completions*' incrementally"                
     nil)
    (const 
     :tag
     "Update `*Completions*' incrementally if already displayed"  
     t)
    (other 
     :tag
     "Update `*Completions*' incrementally always"                
     always))
  :group 'Icicles-Completions-Display)

But _any_ defcustom with a longish :tag in the choice will do.
The :tag string here is only 57 chars wide.
We should be able to display :tag strings up to, say, 70 chars.

You do not need to "reproduce the bug" - you can see what it is.
The :tag string should be shown on a new line, at least when its
length is greater than, say, `(- 70 current-column)', modulo
perhaps some fuzz.