Fix bugs 430, 426, 429, 394, 433.

These bugs are about QApplication instance being destroyed  before
some QObject.

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

tests/QtGui/bug_433.py

@@ -0,0 +1,14 @@
+from PySide import QtCore, QtGui
+import sys
+
+class Test(QtGui.QGraphicsView):
+    def __init__(self, parent=None):
+        super(Test, self).__init__(parent)
+        self.s = QtGui.QGraphicsScene()
+        self.setScene(self.s)
+
+a = QtGui.QApplication(sys.argv)
+t = Test()
+t.show()
+QtCore.QTimer.singleShot(0, t.close)
+sys.exit(a.exec_())