MapGroupObject: forcing removal of children from the engine
MapGroupObject: forcing removal of children from the engine

Fixes memory leaks associated with adding/removal of children
of a QGeoMapGroupObject

Task-number: QTMOBILITY-1275

KDE/android-qt-mobility,qtproject/qt-mobility,tmcguire/qt-mobility,tmcguire/qt-mobility,KDE/android-qt-mobility,kaltsi/qt-mobility,KDE/android-qt-mobility,kaltsi/qt-mobility,kaltsi/qt-mobility,KDE/android-qt-mobility,qtproject/qt-mobility,enthought/qt-mobility,enthought/qt-mobility,qtproject/qt-mobility,kaltsi/qt-mobility,tmcguire/qt-mobility,kaltsi/qt-mobility,qtproject/qt-mobility,enthought/qt-mobility,enthought/qt-mobility,kaltsi/qt-mobility,qtproject/qt-mobility,enthought/qt-mobility,tmcguire/qt-mobility,qtproject/qt-mobility,tmcguire/qt-mobility,enthought/qt-mobility