bug#12218: 24.2.50; vc-ediff: Pressing `n' moves focus away from ediff control panel

[Juri Linkov]

Version: 24.3.50

>> I recommend that this patch be applied. Works for me on my XFCE sytem.
>
> Also verified with "emacs -Q".

Thanks for verifying.  This is now installed in trunk, and the bug is closed.

PS: Note that (fboundp 'select-frame-set-input-focus) is added
for the case when Ediff is used with some other Emacs versions.
Its else-branch is like in `gnus-select-frame-set-input-focus'
in gnus-util.el.