Re: Add -other-{window, frame} variants of project-prefix-map commands

[Juri Linkov]

>> The advantage of other-frame-window is the dedicated keymap that
>> makes all commands to display their buffers in other-window/frame.
>> I think that Emacs core can't have such keymap.
>
> What makes you think Emacs core can't have such a keymap?

I assumed it would be too monumental change.  But maybe it's not.
What it's necessary to do is:

1. Bind ‘C-x 4’ to a new command that will set a transient value of
   display-buffer-overriding-action and a transient keymap to the
   other-window commands keymap.

2. Enable switch-to-buffer-obey-display-actions by default,
   so all buffer-switching commands (e.g. ‘C-h C-t’, ‘C-h C-p’, ‘C-h n’
   and many other such commands) will obey display-buffer-overriding-action.