bug#13122: save-excursion not saving point

[Tino Calancha]

Saving the point, in the general case, would rely on unspecified 
behaviour; so I close this bug.
> > > > ;; Following expression should eval as non-nil
> > > > (let ((pos 3))
> > > >   (with-temp-buffer
> > > >     (insert "abcdef")
> > > >     (goto-char pos)
> > > >     (save-excursion (transpose-chars 2))
> > > >     (= pos (point))))
> > > > => nil
> Since the form inside save-excursion can modify the text before point,
> there is never a guarantee that the numeric value of point stays the
> same.  And if point points inside the modified text, it is generally
> unspecified how point moves during the modification.