Prefer the selected window even with multiple frames

[yoricksijsling]

When the functions purpose-display-reuse-window-buffer and purpose-display-reuse-window-purpose have multiple windows to choose from, they should prefer the selected window. This worked for a single frame, and now it also works over multiple frames.

The issue i had can be reproduced with GNU Emacs 25.3.2 as follows:

1. Start emacs -Q from the
2. Evaluate these statements:

    (require 'cask "~/.cask/cask.el")
    (cask-initialize)
    (add-to-list 'load-path ".")  ;; I started emacs from the window-purpose folder
    (require 'window-purpose)
    (purpose-mode)
   
    (add-to-list 'display-buffer-alist
                 '("." nil (reusable-frames . t)))
   
    (set-frame-name "FIRST FRAME")
    (make-frame '((name . "SECOND FRAME")))

   We should have two frames with names "FIRST FRAME" and "SECOND FRAME", both have a "scratch" buffer open with purpose [edit].
3. From the first frame, use C-x C-f to call purpose-find-file-overload and select a file.

The file is now opened in the second frame, but i expected it to open in the first one.

[coveralls]

Coverage increased (+0.1%) to 67.416% when pulling b173e88 on yoricksijsling:fix-prefer-window-in-same-frame into 2655bbe on bmag:master.

[coveralls]

Coverage increased (+0.1%) to 67.416% when pulling b173e88 on yoricksijsling:fix-prefer-window-in-same-frame into 2655bbe on bmag:master.

[bmag]

Thanks, merged. I did a minor refactor in c75d619