mouse-autoselect-window-select

[Eli Zaretskii]

This change in window.el:

        (mouse-autoselect-window-select): Autoselect only if we are in the
        text portion of the window.

should IMO also trigger auto-selection when the mouse is in the
display margin area of the window.  That's because from the user
perspective the margins are an integral part of the text displayed in
a window, not one of the decorations.  Excluding display margins will
probably surprise users.