Some clean-up related to org-remember being removed

* org.el (org-directory, org-default-notes-file)
(org-reverse-note-order): Don't use the `org-remember'
customization group.
(org-require-autoloaded-modules): Don't require
`org-remember'.

* org-capture.el: Update commentary section to reflect the
fact that org-remember.el is not used anymore.

lisp/org-capture.el

@@ -24,14 +24,14 @@
 ;;
 ;;; Commentary:
 
-;; This file contains an alternative implementation of the same functionality
-;; that is also provided by org-remember.el.  The implementation is more
+;; This file contains an alternative implementation of the functionality
+;; that used to be provided by org-remember.el.  The implementation is more
 ;; streamlined, can produce more target types (e.g. plain list items or
 ;; table lines).  Also, it does not use a temporary buffer for editing
 ;; the captured entry - instead it uses an indirect buffer that visits
 ;; the new entry already in the target buffer (this was an idea by Samuel
-;; Wales).  John Wiegley's excellent `remember.el' is not needed for this
-;; implementation, even though we borrow heavily from its ideas.
+;; Wales).  John Wiegley's excellent `remember.el' is not needed anymore
+;; for this implementation, even though we borrow heavily from its ideas.
 
 ;; This implementation heavily draws on ideas by James TD Smith and
 ;; Samuel Wales, and, of cause, uses John Wiegley's remember.el as inspiration.

lisp/org.el

@@ -2054,16 +2054,14 @@ following situations:
    note buffer with `C-1 C-c C-c'.  The user is prompted for an org file,
    with `org-directory' as the default path."
   :group 'org-refile
-  :group 'org-remember
   :group 'org-capture
   :type 'directory)
 
 (defcustom org-default-notes-file (convert-standard-filename "~/.notes")
   "Default target for storing notes.
-Used as a fall back file for org-remember.el and org-capture.el, for
-templates that do not specify a target file."
+Used as a fall back file for org-capture.el, for templates that
+do not specify a target file."
   :group 'org-refile
-  :group 'org-remember
   :group 'org-capture
   :type '(choice
 	  (const :tag "Default from remember-data-file" nil)
@@ -2093,7 +2091,6 @@ outline-path-completion  Headlines in the current buffer are offered via
 When nil, new notes will be filed to the end of a file or entry.
 This can also be a list with cons cells of regular expressions that
 are matched against file names, and values."
-  :group 'org-remember
   :group 'org-capture
   :group 'org-refile
   :type '(choice
@@ -21082,7 +21079,7 @@ Your bug report will be posted to the Org-mode mailing list.
   (interactive)
   (mapc 'require
 	'(org-agenda org-archive org-attach org-clock org-colview org-id
-		     org-remember org-table org-timer)))
+		     org-table org-timer)))
 
 ;;;###autoload
 (defun org-reload (&optional uncompiled)