bug#5809: 23.1.94; cross-reference by anchor yields in accurate position

[Drew Adams]

> A possible change: Add a menu item `Customize Breadcrumbs 
> Depth' for customizing
> `Info-breadcrumbs-depth', the default depth.
> 
> Another possible change: Put back the size indication mode 
> when breadcrumbs are
> shown. I don't miss it (the scroll bar is enough), but you 
> might want it. There
> is probably room for it, even for manuals that have several 
> levels and long node
> names.
> 
> Another possible change: put back the read-only/writable 
> indicator. Or perhaps
> just turn off breadcrumbs mode whenever someone edits an Info node.

Another possible change: Put `Info-scroll-up'/`down' on mouse-1/mouse-3 for the
current node name (similar to what is the case now).