Borrow fill-or-unfill-paragraph from sachachua

init.el

@@ -1048,6 +1048,7 @@
  ("M-t W" . transpose-windows)
  ("C-a" . gpolonkai/move-to-beginning-of-line)
  ("C-e" . gpolonkai/move-to-end-of-line)
+ ("M-q" . sachachua/fill-or-unfill-paragraph)
  :map ctl-x-map
  ("C-y" . duplicate-line)
  ("_" . maximize-window)

lisp/text-manip.el

@@ -5,3 +5,13 @@
   (when (looking-back "[.!?…]")
     (call-interactively 'self-insert-command arg))
   (call-interactively 'self-insert-command arg))
+
+;; From http://pages.sachachua.com/.emacs.d/Sacha.html
+(defun sachachua/fill-or-unfill-paragraph (&optional unfill region)
+  "Fill paragraph (or REGION).
+  With the prefix argument UNFILL, unfill it instead."
+  (interactive (progn
+                 (barf-if-buffer-read-only)
+                 (list (if current-prefix-arg 'unfill) t)))
+  (let ((fill-column (if unfill (point-max) fill-column)))
+    (fill-paragraph nil region)))