Define externally accessible classes and constants with 'var'.

Avoid warnings following the updated of Gjs to mozjs-52i (GNOME Shell
3.26), as per ES6 standard.

Author: micheleg

appIcons.js

@@ -88,7 +88,7 @@ const DOMINANT_COLOR_ICON_SIZE = 64;
  * - Update menu if open on windows change
  * - Unity7-esk backlit item emulation
  */
-const MyAppIcon = new Lang.Class({
+var MyAppIcon = new Lang.Class({
     Name: 'DashToDock.AppIcon',
     Extends: AppDisplay.AppIcon,
 

dash.js

@@ -175,7 +175,7 @@ const baseIconSizes = [16, 22, 24, 32, 48, 64, 96, 128];
  * - sync minimization application target position.
  * - keep running apps ordered.
  */
-const MyDash = new Lang.Class({
+var MyDash = new Lang.Class({
     Name: 'DashToDock.MyDash',
 
     _init: function(settings, monitorIndex) {

docking.js

@@ -1632,7 +1632,7 @@ const WorkspaceIsolation = new Lang.Class({
 });
 
 
-const DockManager = new Lang.Class({
+var DockManager = new Lang.Class({
     Name: 'DashToDock.DockManager',
 
     _init: function() {

intellihide.js

@@ -45,7 +45,7 @@ const handledWindowTypes = [
  * Intallihide object: emit 'status-changed' signal when the overlap of windows
  * with the provided targetBoxClutter.ActorBox changes;
  */
-const Intellihide = new Lang.Class({
+var Intellihide = new Lang.Class({
     Name: 'DashToDock.Intellihide',
 
     _init: function(settings, monitorIndex) {

theming.js

@@ -28,7 +28,7 @@ const Utils = Me.imports.utils;
 /**
  * Manage theme customization and custom theme support
  */
-const ThemeManager = new Lang.Class({
+var ThemeManager = new Lang.Class({
     Name: 'DashToDock.ThemeManager',
 
     _init: function(settings, actor, dash) {

utils.js

@@ -64,7 +64,7 @@ const BasicHandler = new Lang.Class({
 /**
  * Manage global signals
  */
-const GlobalSignalsHandler = new Lang.Class({
+var GlobalSignalsHandler = new Lang.Class({
     Name: 'DashToDock.GlobalSignalHandler',
     Extends: BasicHandler,
 
@@ -85,7 +85,7 @@ const GlobalSignalsHandler = new Lang.Class({
 /**
  * Color manipulation utilities
   */
-const ColorUtils = {
+var ColorUtils = {
 
     // Darken or brigthen color by a fraction dlum
     // Each rgb value is modified by the same fraction.
@@ -184,7 +184,7 @@ const ColorUtils = {
  * Manage function injection: both instances and prototype can be overridden
  * and restored
  */
-const InjectionsHandler = new Lang.Class({
+var InjectionsHandler = new Lang.Class({
     Name: 'DashToDock.InjectionsHandler',
     Extends: BasicHandler,