dired-mouse-drag-files

[Eli Zaretskii]

This feature is not universally available, but is doc string doesn't
say so (the manual does).

Moreover, setting the variable non-nil unconditionally shows a tooltip
on file names in Dired buffers saying that the user can drag the file
to another program, but that is only so on X; on other platforms it's
a misleading tooltip.

As an aside, changing the value of the variable doesn't affect the
Dired buffers that already exist, only those created afterwards, which
I think is not the best UX.

Can you please fix these issues?

Thanks.