bug#24213: 25.1.50; Fishy use of delete-window in register.el

[Andreas Politz]

The register.el commands display a preview of register contents, using
display-buffer in register-preview.  Later, when some register was
chosen by the user, the window showing this preview is closed via
delete-window.

It seems to me, that this call should be replaced by a call to
quit-window, because this function does the right thing: It only deletes
the window if it was previously created and otherwise shows the previous
buffer in that window.

If that analysis can be agreed upon: Grepping through lisp/*, I found 62
uses of delete-window outside window.el.  I assume that most of those
applications are problematic in the same way (e.g. finder.el).

-Andreas