Revert "Lua dialogs: remove b_hide parameter"

This reverts commit 67875950.

include/vlc_extensions.h

@@ -195,6 +195,7 @@ struct extension_dialog_t
 
     DECL_ARRAY(extension_widget_t*) widgets; ///< Widgets owned by the dialog
 
+    bool b_hide;                 ///< Hide this dialog (!b_hide shows)
     bool b_kill;                 ///< Kill this dialog
 
     void *p_sys;                 ///< Dialog private pointer

modules/gui/qt4/dialogs/extensions.cpp

@@ -112,13 +112,14 @@ ExtensionDialog* ExtensionsDialogProvider::UpdateExtDialog(
     if( !p_dialog->b_kill && !dialog )
     {
         dialog = CreateExtDialog( p_dialog );
-        dialog->setVisible( true );
+        dialog->setVisible( !p_dialog->b_hide );
     }
     else if( !p_dialog->b_kill && dialog )
     {
         dialog->has_lock = true;
         dialog->UpdateWidgets();
         dialog->has_lock = false;
+        dialog->setVisible( !p_dialog->b_hide );
     }
     else if( p_dialog->b_kill )
     {