AUP3: Make suggested directory preferences changes

In addition, I've extracted the wxTextCtrl wrapper from the
TimerRecordDialog intto widgets/wxTextCtrlWrapper.h and made
it the default for ShuttleGui::AddTextBox(). This way readonly
text controls are always included in the tab order.

src/export/ExportFFmpegDialogs.cpp

@@ -809,7 +809,6 @@ void ExportFFmpegCustomOptions::PopulateOrExchange(ShuttleGui & S)
          }
          S.EndMultiColumn();
       }
-#
       S.EndHorizontalLay();
    }
    S.EndHorizontalLay();