bug#457: wdired and auto-revert-mode

[martin rudalics]

> The correct way to handle this is to mark the buffer as modified
> during the period for which it should not be auto-reverted.

No.  `buffer-modified-p' is busy telling whether the user has modified
the buffer with `wdired'.  It's used many times in wdired.el.

> The
> function auto-revert-handler refuses to do anything with buffers that
> are marked as modified.  The first thing auto-revert-handler does is
> check the condition (buffer-modified-p).

martin