hide some controls from preferences pages that are not implemented yet

src/Gui/DlgEditorImp.cpp

@@ -57,6 +57,8 @@ DlgSettingsEditorImp::DlgSettingsEditorImp( QWidget* parent )
   : PreferencePage( parent )
 {
     this->setupUi(this);
+    this->EnableFolding->hide(); // Switch off until we have an editor with folding
+
     d = new DlgSettingsEditorP();
     QColor col;
     col = Qt::black;