Add lexical binding cookies (#389)

* Add lexical binding cookies

* multiple-cursors-core.el: Pacify lexical-binding frenzy in master

* multiple-cursors-core.el: when saving mc/list-file, prepend a
lexical binding flag to avoid emacs master from screaming.  When
inserting strings, use `\\n' instead of (newline).

mc-cycle-cursors.el

@@ -1,4 +1,4 @@
-;;; mc-cycle-cursors.el
+;;; mc-cycle-cursors.el  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2012-2016 Magnar Sveen
 

mc-edit-lines.el

@@ -1,4 +1,4 @@
-;;; mc-edit-lines.el
+;;; mc-edit-lines.el  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2012-2016 Magnar Sveen
 

mc-hide-unmatched-lines-mode.el

@@ -1,4 +1,4 @@
-;;; mc-hide-unmatched-lines-mode.el
+;;; mc-hide-unmatched-lines-mode.el  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2014 Aleksey Fedotov
 

mc-mark-more.el

@@ -1,4 +1,4 @@
-;;; mc-mark-more.el
+;;; mc-mark-more.el  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2012-2016 Magnar Sveen
 

mc-mark-pop.el

@@ -1,4 +1,4 @@
-;;; mc-mark-pop.el --- Pop cursors off of the mark stack
+;;; mc-mark-pop.el --- Pop cursors off of the mark stack  -*- lexical-binding: t; -*-
 
 (require 'multiple-cursors-core)
 

mc-separate-operations.el

@@ -1,4 +1,4 @@
-;;; mc-separate-operations.el - functions that work differently on each cursor
+;;; mc-separate-operations.el - functions that work differently on each cursor  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2012-2016 Magnar Sveen
 

multiple-cursors-core.el

@@ -1,4 +1,4 @@
-;;; multiple-cursors-core.el --- An experiment in multiple cursors for emacs.
+;;; multiple-cursors-core.el --- An experiment in multiple cursors for emacs.  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2012-2016 Magnar Sveen
 
@@ -885,11 +885,10 @@ for running commands with multiple cursors."
   "Saves preferences for running commands with multiple cursors to `mc/list-file'"
   (with-temp-file mc/list-file
     (emacs-lisp-mode)
-    (insert ";; This file is automatically generated by the multiple-cursors extension.")
-    (newline)
-    (insert ";; It keeps track of your preferences for running commands with multiple cursors.")
-    (newline)
-    (newline)
+    (when (> emacs-major-version 30)
+      (insert ";;   -*- lexical-binding: t; -*-\n"))
+    (insert ";; This file is automatically generated by the multiple-cursors extension.\n")
+    (insert ";; It keeps track of your preferences for running commands with multiple cursors.\n\n")
     (mc/dump-list 'mc/cmds-to-run-for-all)
     (newline)
     (mc/dump-list 'mc/cmds-to-run-once)))

multiple-cursors.el

@@ -1,4 +1,4 @@
-;;; multiple-cursors.el --- Multiple cursors for emacs.
+;;; multiple-cursors.el --- Multiple cursors for emacs.  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2012-2016 Magnar Sveen
 

rectangular-region-mode.el

@@ -1,4 +1,4 @@
-;;; rectangular-region-mode.el
+;;; rectangular-region-mode.el  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2012-2016 Magnar Sveen