Make debug local

Add `Extension` and `debug` to all the module scopes for convenience.

(also add var to non-used function)

extension.js

@@ -4,6 +4,7 @@ const Tiling = Extension.imports.tiling;
 const Scratch = Extension.imports.scratch;
 const LiveAltTab = Extension.imports.liveAltTab;
 const utils = Extension.imports.utils;
+const debug = utils.debug;
 const Gio = imports.gi.Gio;
 const GLib = imports.gi.GLib;
 const Meta = imports.gi.Meta;

liveAltTab.js

@@ -9,6 +9,8 @@ let WindowManager = imports.ui.windowManager;
 const Extension = imports.misc.extensionUtils.getCurrentExtension();
 const Scratch = Extension.imports.scratch;
 const Tiling = Extension.imports.tiling;
+const utils = Extension.imports.utils;
+const debug = utils.debug;
 
 WindowManager.WindowManager.prototype._previewWorkspace = function(from, to, direction) {
 

minimap.js

@@ -9,6 +9,8 @@ const Meta = imports.gi.Meta;
 const Pango = imports.gi.Pango;
 
 const Tiling = Extension.imports.tiling;
+const utils = Extension.imports.utils;
+const debug = utils.debug;
 
 var MINIMAP_SCALE = 0.15;
 

scratch.js

@@ -1,4 +1,7 @@
+const Extension = imports.misc.extensionUtils.getCurrentExtension();
 const Meta = imports.gi.Meta;
+const utils = Extension.imports.utils;
+const debug = utils.debug;
 
 function isScratchWindow(metaWindow) {
     return metaWindow.is_on_all_workspaces();

stackoverlay.js

@@ -5,6 +5,8 @@ const Tweener = imports.ui.tweener;
 const Lang = imports.lang;
 const Main = imports.ui.main;
 const Shell = imports.gi.Shell;
+const utils = Extension.imports.utils;
+const debug = utils.debug;
 
 /*
   The stack overlay decorates the top stacked window with its icon and

tiling.js

@@ -8,6 +8,7 @@ const Main = imports.ui.main;
 const Shell = imports.gi.Shell;
 const Gio = imports.gi.Gio;
 const utils = Extension.imports.utils;
+const debug = utils.debug;
 const Clutter = imports.gi.Clutter;
 
 var Minimap = Extension.imports.minimap;

utils.js

@@ -1,7 +1,7 @@
 
 var debug_all = true; // Consider the default value in `debug_filter` to be true
 var debug_filter = { "#preview": false };
-debug = function() {
+var debug = function() {
     let keyword = arguments[0];
     let filter = debug_filter[keyword];
     if (filter === false)
@@ -82,7 +82,7 @@ var setDevGlobals = function() {
 /**
  * Visualize the frame and buffer bounding boxes of a meta window
  */
-toggleWindowBoxes = function(metaWindow) {
+var toggleWindowBoxes = function(metaWindow) {
     metaWindow = metaWindow || global.display.focus_window;
 
     if(metaWindow._paperDebugBoxes) {