title: Signals returnPressed() and editingFinished() does not work for QLineEdit
body: <p>I am using <code>editingFinished()</code> signals of <code>QLineEdit</code> to perform an Operation. The documentation says that this signal will be emitted when return or enter key is pressed or when it will lose focus. </p>
  
  <p>It works well with the <code>enter key</code> on the numlock (<code>Windows</code> keyboard), and also when it loses focus, but when i press "return key" on the keyboard, the signal is not emitted. i tried to use the <code>returnPressed()</code> signal, it behaves the same way.</p>
  
  <p>Am i missing something ?</p>
  
  <p>Thank you </p>