bug#34503: dired-do-copy: full disclosure

[積丹尼 Dan Jacobson]

C runs the command dired-do-copy (found in dired-mode-map), which is
an interactive autoloaded compiled Lisp function in ‘dired-aux.el’.

OK but even though it asks "Recursive copy of directory?" etc.
its final line is always "Copied 1 file".

Please have it say "Copied 2387 files, 141 directories" else we always
have to double check if it really ever copied more than one file you
see. Computers are fast these days.

Yes you can argue (hmmm, I think we argued about this before) that a
directory is a file. But cp -v shows more that one...

Anyway simply keep track of how many files and directories were copied
and report it.

But wait, then we lose the safety feature of: "I forgot how many marks I
made. In fact I had marked two directories, so good thing it said copied
2 files."

OK, say "Copied 2 trees, 47 directories, 234 files." Something like
that.

And only say "trees" when more than one directory is marked...

But what if they had marked one directory and one file...

Same for Rename (R).