Fixed signal/slot class name based on PSEP 100.

Reviewer: Hugo Parente Lima <hugo.lima@openbossa.org>,
          Luciano Wolf <luciano.wolf@openbossa.org>

tests/signals/ref04_test.py

@@ -2,11 +2,11 @@
 # -*- coding: utf-8 -*-
 
 import unittest
-from PySide.QtCore import QObject, Signal
+from PySide.QtCore import QObject, signal
 
 class ExtQObject(QObject):
 
-    mySignal = Signal()
+    mySignal = signal()
 
     def __init__(self):
         QObject.__init__(self)