Define classes with 'var' instead of 'const'

Any symbols (including class properties) that should be visible
outside the module it's defined in need to be defined as global.
For now gjs still allows the access for 'const', but get rid of
the warnings spill now by changing it.

https://bugzilla.gnome.org/show_bug.cgi?id=785084

js/gdm/authPrompt.js

@@ -38,7 +38,7 @@ const BeginRequestType = {
     DONT_PROVIDE_USERNAME: 1
 };
 
-const AuthPrompt = new Lang.Class({
+var AuthPrompt = new Lang.Class({
     Name: 'AuthPrompt',
 
     _init: function(gdmClient, mode) {

js/gdm/batch.js

@@ -47,7 +47,7 @@
 const Lang = imports.lang;
 const Signals = imports.signals;
 
-const Task = new Lang.Class({
+var Task = new Lang.Class({
     Name: 'Task',
 
     _init: function(scope, handler) {
@@ -68,7 +68,7 @@ const Task = new Lang.Class({
 });
 Signals.addSignalMethods(Task.prototype);
 
-const Hold = new Lang.Class({
+var Hold = new Lang.Class({
     Name: 'Hold',
     Extends: Task,
 
@@ -110,7 +110,7 @@ const Hold = new Lang.Class({
 });
 Signals.addSignalMethods(Hold.prototype);
 
-const Batch = new Lang.Class({
+var Batch = new Lang.Class({
     Name: 'Batch',
     Extends: Task,
 
@@ -185,7 +185,7 @@ const Batch = new Lang.Class({
 });
 Signals.addSignalMethods(Batch.prototype);
 
-const ConcurrentBatch = new Lang.Class({
+var ConcurrentBatch = new Lang.Class({
     Name: 'ConcurrentBatch',
     Extends: Batch,
 
@@ -204,7 +204,7 @@ const ConcurrentBatch = new Lang.Class({
 });
 Signals.addSignalMethods(ConcurrentBatch.prototype);
 
-const ConsecutiveBatch = new Lang.Class({
+var ConsecutiveBatch = new Lang.Class({
     Name: 'ConsecutiveBatch',
     Extends: Batch,
 

js/gdm/loginDialog.js

@@ -51,7 +51,7 @@ const _TIMED_LOGIN_IDLE_THRESHOLD = 5.0;
 const _LOGO_ICON_HEIGHT = 48;
 const _MAX_BOTTOM_MENU_ITEMS = 5;
 
-const UserListItem = new Lang.Class({
+var UserListItem = new Lang.Class({
     Name: 'UserListItem',
 
     _init: function(user) {
@@ -145,7 +145,7 @@ const UserListItem = new Lang.Class({
 });
 Signals.addSignalMethods(UserListItem.prototype);
 
-const UserList = new Lang.Class({
+var UserList = new Lang.Class({
     Name: 'UserList',
 
     _init: function() {
@@ -296,7 +296,7 @@ const UserList = new Lang.Class({
 });
 Signals.addSignalMethods(UserList.prototype);
 
-const SessionMenuButton = new Lang.Class({
+var SessionMenuButton = new Lang.Class({
     Name: 'SessionMenuButton',
 
     _init: function() {
@@ -402,7 +402,7 @@ const SessionMenuButton = new Lang.Class({
 });
 Signals.addSignalMethods(SessionMenuButton.prototype);
 
-const LoginDialog = new Lang.Class({
+var LoginDialog = new Lang.Class({
     Name: 'LoginDialog',
 
     _init: function(parentActor) {

js/gdm/oVirt.js

@@ -27,7 +27,7 @@ function OVirtCredentials() {
     return self;
 }
 
-const OVirtCredentialsManager = new Lang.Class({
+var OVirtCredentialsManager = new Lang.Class({
     Name: 'OVirtCredentialsManager',
     _init: function() {
         this._token = null;

js/gdm/realmd.js

@@ -59,7 +59,7 @@ const RealmIface = '<node> \
 </node>';
 const Realm = Gio.DBusProxy.makeProxyWrapper(RealmIface);
 
-const Manager = new Lang.Class({
+var Manager = new Lang.Class({
     Name: 'Manager',
 
     _init: function(parentActor) {

js/gdm/util.js

@@ -119,7 +119,7 @@ function cloneAndFadeOutActor(actor) {
     return hold;
 }
 
-const ShellUserVerifier = new Lang.Class({
+var ShellUserVerifier = new Lang.Class({
     Name: 'ShellUserVerifier',
 
     _init: function(client, params) {