Improve StorageInfo QML element documentation
Improve StorageInfo QML element documentation

Added missing properties, signals and methods

Task-number: QTMOBILITY-1875

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