Fixes bug #502.

The ownership of the editor returned by the Python override of
QAbstractItemDelegate.createEditor(...) is now transferred to C++.

A test was added to simulate the situation that triggers the bug,
instead of relying on an example with a view, model and editable cells.

See: http://bugs.openbossa.org/show_bug.cgi?id=502

Reviewed by Lauro Moura <lauro.neto@openbossa.org>
Reviewed by Renato Araújo <renato.filho@openbossa.org>

tests/pysidetest/testview.h

@@ -2,12 +2,15 @@
 #define TESTVIEW_H
 
 #include <QObject>
-#include <QAbstractListModel>
 #ifdef pysidetest_EXPORTS
 #define PYSIDE_EXPORTS 1
 #endif
 #include "pysidemacros.h"
 
+class QWidget;
+class QAbstractListModel;
+class QAbstractItemDelegate;
+
 class PYSIDE_API TestView : public QObject
 {
     Q_OBJECT
@@ -15,8 +18,13 @@ public:
     TestView(QAbstractListModel* model, QObject* parent = 0) : QObject(parent), m_model(model) {}
     QAbstractListModel* model() { return m_model; }
     QVariant getData();
+
+    void setItemDelegate(QAbstractItemDelegate* delegate) { m_delegate = delegate; }
+    QWidget* getEditorWidgetFromItemDelegate() const;
+
 private:
     QAbstractListModel* m_model;
+    QAbstractItemDelegate* m_delegate;
 };
 
 #endif // TESTVIEW_H