Following signals parameters are wrongly documented:

void rowsAboutToBeInserted(const QModelIndex &parent, int first, int last)
void rowsInserted(const QModelIndex &parent, int first, int last)
void rowsAboutToBeRemoved(const QModelIndex &parent, int first, int last)
void rowsRemoved(const QModelIndex &parent, int first, int last)
void columnsAboutToBeInserted(const QModelIndex &parent, int first, int last)
void columnsInserted(const QModelIndex &parent, int first, int last)
void columnsAboutToBeRemoved(const QModelIndex &parent, int first, int last)
void columnsRemoved(const QModelIndex &parent, int first, int last)

the second and third parameter Instead of "first and last" document says "start and end" and this create problem if it is being used in QML.

for example:
void QAbstractItemModel::rowsAboutToBeInserted(const QModelIndex & parent, int start, int end)
http://qt-project.org/doc/qt-5.0/qtcore/qabstractitemmodel.html#rowsAboutToBeInserted