Unsynchronised file editing.

[chris glur <crglur gmail com>]

Is it mcedit's or the OS's job to prevent multiple editing
of the same file.  I noticed that Win7 doesn't allow a file
to be changed when a different/another task has got that same
file open. Under linux, I only use mc to edit text-files, so
I don't know if editors other than mcedit, prevent the potential
problem.

I use `lsof` to see which directories are being used [by mc];
and since it means "lïst open FILES", I guess it should be able
to show the open FILES, and not only the directories.

== Chris Glur.