bug#44895: [External] : bug#44895: Add Info-copy-permalink

[Drew Adams]

> > Did you bind it to a key?  Info+ binds it to `G', and
> > that'd be my suggestion for Emacs also.  It goes to a
> > node, just like `g'; it just goes to it in the manual
> > on the web.
> 
> For symmetry we could use such keybindings:
> 
>   "g" 'Info-goto-node
>   "G" 'Info-goto-node-web
> 
>   "w" 'Info-copy-current-node-name
>   "W" 'Info-url-for-node

Good idea for W.  (I've added that binding now to Info+.)