Remove releaseWrapper as Signal tp_dealloc

It was being called when the Signal was garbage
collected, resulting in a segfault.

Reviewer: Luciano Wolf <luciano.wolf@openbossa.org>
Reviewer: Renato Filho <renato.filho@openbossa.org>

tests/signals/leaking_signal_test.py

@@ -0,0 +1,16 @@
+
+import unittest
+from PySide import QtCore
+import weakref
+
+class LeakingSignal(unittest.TestCase):
+
+    def testLeakingSignal(self):
+        # Was segfaulting when the signal was garbage collected.
+        class Emitter(QtCore.QObject):
+            my_signal = QtCore.Signal(object)
+
+        emitter = Emitter()
+
+if __name__ == '__main__':
+    unittest.main()