bug#11795: 24.1.50; wdired: C-c C-c loses marks and positions of renamed files

[Juri Linkov]

> Instead of this, much simpler would be to keep the current design
> of WDired that uses `revert-buffer' to maintain consistency with renames.
> Then a simpler fix would be to call `revert-buffer' in all other
> Dired buffers that display renamed files by using
>
>   (dired-fun-in-all-buffers dired-directory nil (function revert-buffer))

After looking more at this, I noticed a problem that no previous patch
was able to fix.

The question is what to do with marks in other Dired buffers?

One option is to copy marks of renamed files from the current Dired buffer
to other Dired buffers that display the same set of renamed files.
But I think that more correct would be to remember marks in all other
Dired buffers, and in `wdired-finish-edit' restore them in other Dired
buffer to their previous marks.

This means that `wdired-old-marks' should be an associative list
where the key is a Dired buffer and the value is the returned value
from `dired-remember-marks' remembered for each Dired buffer.