Clarify the lifetime expectations of the device for QVersitReader.
Clarify the lifetime expectations of the device for QVersitReader.

Change-Id: I656ab6c3247880b4ba20874dbe55145a350a37c4
Task-number: MOBILITY-1846

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