bug#9419: 24.0.50; C-x k deletes the entire frame instead of switching to another buffer

[martin rudalics]

> However, this use case looks inconsistent, or maybe I don't understand
> the intended behavior:
>
>   emacs -Q
>   C-x 5 b foo RET
>
> then in the new frame:
>
>   C-x b bar RET
>   C-x b foo RET
>   C-x k RET      (kills the foo buffer and shows bar)
>   C-x k RET      (kills the bar buffer and shows *scratch*)
>
> My understanding of the intended behavior is that since foo and bar
> are the only 2 buffers in that frame's buffer list, the frame should
> be deleted after the last one of them is deleted.  But in fact the
> frame stays alive and shows *scratch*.
>
> If I kill the buffers in the reverse order, i.e. bar first and then
> foo, the frame does get deleted when foo is killed.

I hopefully made these cases consistent now.  In addition, the option
`window-auto-delete' can be used to tune down auto-deletion if wanted.

martin