Improve speedup/slowdown used in debugging

TestWindow.py

@@ -105,6 +105,7 @@ class HearingTestThread(QtCore.QThread):
 class TestWindow(QMainWindow):
 
     start_text = "Press space to start..."
+    slowdown = 10
 
     def __init__(self, library):
         QMainWindow.__init__(self)
@@ -158,10 +159,10 @@ class TestWindow(QMainWindow):
                 self.log.hide()
             return
         if event.key() == Qt.Qt.Key_F:
-            HearingTest.max_response_time = 0.01
+            HearingTest.max_response_time /= self.slowdown
             return
         if event.key() == Qt.Qt.Key_S:
-            HearingTest.max_response_time = 1
+            HearingTest.max_response_time *= self.slowdown
             return
         if not self.test_running:
             if event.key() == Qt.Qt.Key_Escape: