emacs: Improve interactive use documentation

This improves the function documentation for many interactive
commands, either by improving their documentation string where the
improvement also makes sense for programmatic use or by adding a
'notmuch-doc property where it doesn't.

For nearly all commands that support a prefix argument, this adds a
'notmuch-prefix-doc property to document their prefixed behavior This
omits prefix documentation for a few commands where I thought the
prefixed behavior was too obscure (or too complex to fit in one line).

emacs/notmuch-mua.el

@@ -313,8 +313,9 @@ the From: header is already filled in by notmuch."
       (ido-completing-read "Send mail From: " notmuch-identities
 			   nil nil nil 'notmuch-mua-sender-history (car notmuch-identities)))))
 
+(put 'notmuch-mua-new-mail 'notmuch-prefix-doc "... and prompt for sender")
 (defun notmuch-mua-new-mail (&optional prompt-for-sender)
-  "Invoke the notmuch mail composition window.
+  "Compose new mail.
 
 If PROMPT-FOR-SENDER is non-nil, the user will be prompted for
 the From: address first."

emacs/notmuch-show.el

@@ -1488,6 +1488,8 @@ current thread."
   "Are the headers of the current message visible?"
   (notmuch-show-get-prop :headers-visible))
 
+(put 'notmuch-show-mark-read 'notmuch-prefix-doc
+     "Mark the current message as unread.")
 (defun notmuch-show-mark-read (&optional unread)
   "Mark the current message as read.
 
@@ -1609,16 +1611,20 @@ any effects from previous calls to
       ;; Move to the previous message.
       (notmuch-show-previous-message)))))
 
+(put 'notmuch-show-reply 'notmuch-prefix-doc "... and prompt for sender")
 (defun notmuch-show-reply (&optional prompt-for-sender)
   "Reply to the sender and all recipients of the current message."
   (interactive "P")
   (notmuch-mua-new-reply (notmuch-show-get-message-id) prompt-for-sender t))
 
+(put 'notmuch-show-reply-sender 'notmuch-prefix-doc "... and prompt for sender")
 (defun notmuch-show-reply-sender (&optional prompt-for-sender)
   "Reply to the sender of the current message."
   (interactive "P")
   (notmuch-mua-new-reply (notmuch-show-get-message-id) prompt-for-sender nil))
 
+(put 'notmuch-show-forward-message 'notmuch-prefix-doc
+     "... and prompt for sender")
 (defun notmuch-show-forward-message (&optional prompt-for-sender)
   "Forward the current message."
   (interactive "P")
@@ -1722,6 +1728,10 @@ to show, nil otherwise."
     (set-buffer-modified-p nil)
     (view-buffer buf 'kill-buffer-if-not-modified)))
 
+(put 'notmuch-show-pipe-message 'notmuch-doc
+     "Pipe the contents of the current message to a command.")
+(put 'notmuch-show-pipe-message 'notmuch-prefix-doc
+     "Pipe the thread as an mbox to a command.")
 (defun notmuch-show-pipe-message (entire-thread command)
   "Pipe the contents of the current message (or thread) to COMMAND.
 
@@ -1795,12 +1805,16 @@ See `notmuch-tag' for information on the format of TAG-CHANGES."
 	 (notmuch-show-set-tags new-tags))))))
 
 (defun notmuch-show-add-tag ()
-  "Same as `notmuch-show-tag' but sets initial input to '+'."
+  "Change tags for the current message (defaulting to add).
+
+Same as `notmuch-show-tag' but sets initial input to '+'."
   (interactive)
   (notmuch-show-tag "+"))
 
 (defun notmuch-show-remove-tag ()
-  "Same as `notmuch-show-tag' but sets initial input to '-'."
+  "Change tags for the current message (defaulting to remove).
+
+Same as `notmuch-show-tag' but sets initial input to '-'."
   (interactive)
   (notmuch-show-tag "-"))
 
@@ -1822,6 +1836,8 @@ See `notmuch-tag' for information on the format of TAG-CHANGES."
      (not (plist-get props :message-visible))))
   (force-window-update))
 
+(put 'notmuch-show-open-or-close-all 'notmuch-doc "Show all messages.")
+(put 'notmuch-show-open-or-close-all 'notmuch-prefix-doc "Hide all messages.")
 (defun notmuch-show-open-or-close-all ()
   "Set the visibility all of the messages in the current thread.
 
@@ -1873,6 +1889,8 @@ search results instead."
   (interactive)
   (notmuch-show-next-thread t t))
 
+(put 'notmuch-show-archive-thread 'notmuch-prefix-doc
+     "Un-archive each message in thread.")
 (defun notmuch-show-archive-thread (&optional unarchive)
   "Archive each message in thread.
 
@@ -1902,6 +1920,8 @@ buffer."
   (notmuch-show-archive-thread)
   (notmuch-show-next-thread))
 
+(put 'notmuch-show-archive-message 'notmuch-prefix-doc
+     "Un-archive the current message.")
 (defun notmuch-show-archive-message (&optional unarchive)
   "Archive the current message.
 
@@ -1953,6 +1973,8 @@ thread from search."
   (interactive)
   (notmuch-common-do-stash (notmuch-show-get-from)))
 
+(put 'notmuch-show-stash-message-id 'notmuch-prefix-doc
+     "Copy thread: query matching current thread to kill-ring.")
 (defun notmuch-show-stash-message-id (&optional stash-thread-id)
   "Copy id: query matching the current message to kill-ring.
 

emacs/notmuch.el

@@ -575,15 +575,21 @@ See `notmuch-tag' for information on the format of TAG-CHANGES."
     (notmuch-search-tag-region beg end tag-changes)))
 
 (defun notmuch-search-add-tag ()
-  "Same as `notmuch-search-tag' but sets initial input to '+'."
+  "Change tags for the current thread (defaulting to add).
+
+Same as `notmuch-search-tag' but sets initial input to '+'."
   (interactive)
   (notmuch-search-tag "+"))
 
 (defun notmuch-search-remove-tag ()
-  "Same as `notmuch-search-tag' but sets initial input to '-'."
+  "Change tags for the current thread (defaulting to remove).
+
+Same as `notmuch-search-tag' but sets initial input to '-'."
   (interactive)
   (notmuch-search-tag "-"))
 
+(put 'notmuch-search-archive-thread 'notmuch-prefix-doc
+     "Un-archive the currently selected thread.")
 (defun notmuch-search-archive-thread (&optional unarchive)
   "Archive the currently selected thread.
 
@@ -887,6 +893,7 @@ PROMPT is the string to prompt with."
 			      'notmuch-search-history nil nil)))))
 
 ;;;###autoload
+(put 'notmuch-search 'notmuch-doc "Search for messages.")
 (defun notmuch-search (&optional query oldest-first target-thread target-line)
   "Display threads matching QUERY in a notmuch-search buffer.