dired-do-delete: Allow to delete dirs recursively without prompts

* lisp/dired.el (dired-delete-file): Accept 2 additional answers:
'all', to delete all directories recursively and no prompt anymore.
'quit', to cancel directory deletions (Bug#27940).
Show help message when user inputs 'help'.
(dired-do-flagged-delete): Bind locally dired-recursive-deletes
so that we can overwrite its global value.
Wrapp the loop within a catch '--delete-cancel to catch when
the user abort the directtry deletion.
* doc/emacs/dired.texi (Dired Deletion): Update manual.
* etc/NEWS (Changes in Specialized Modes and Packages in Emacs 26.1):
Announce this change.

1 files changed, 8 insertions, 0 deletions

diff --git a/doc/emacs/dired.texi b/doc/emacs/dired.texi
index 150ac8427ab..c1cc2f8cf96 100644
--- a/doc/emacs/dired.texi
+++ b/doc/emacs/dired.texi
@@ -236,6 +236,14 @@ Dired cannot delete directories that are nonempty.  If the variable
 @code{dired-recursive-deletes} is non-@code{nil}, then Dired can
 delete nonempty directories including all their contents.  That can
 be somewhat risky.
+Even if you have set @code{dired-recursive-deletes} to @code{nil},
+you might want sometimes to delete recursively directories
+without being asked for confirmation for all of them.  This is handy
+when you have marked many directories for deletion and you are very
+sure that all of them can safely being deleted.  For every nonempty
+directory you are asked for confirmation; if you answer @code{all},
+then all the remaining directories will be deleted without more
+questions.
 
 @vindex delete-by-moving-to-trash
   If you change the variable @code{delete-by-moving-to-trash} to