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_430.py

@@ -0,0 +1,14 @@
+import sys
+from PySide.QtCore import *
+from PySide.QtGui import *
+
+class ListModel(QAbstractListModel):
+    def rowCount(self, parent = QModelIndex()):
+        return len(self._items)
+
+app = QApplication([])
+model = ListModel()
+v = QListView()
+v.setModel(model)
+QTimer.singleShot(0, v.close)
+app.exec_()