position table now retains row values when adding new rows

  void JigsawSetupDialog::on_spkSolveDegreeSpinBox_valueChanged(int i) {

    // number of rows == spkSolveDegree value + 1 (i+1)

    QTableWidget *table = m_ui->positionAprioriSigmaTable;

    const int oldRowCount = table->rowCount();

    table->setRowCount(i + 1);

    const int newRowCount = table->rowCount();

    const int columnCount = table->columnCount();

    // Headers : coefficient, description, units, a priori sigma

    // The description and units are related directly to the solve options, so for now do those

    // generically (columns 1 and 2)

    for (int row = 0; row < i + 1; row++) {

    if (newRowCount > oldRowCount) {

      for (int row = oldRowCount; row < newRowCount; row++) {

        QTableWidgetItem *coefficient = new QTableWidgetItem();

        coefficient->setFlags(Qt::ItemIsEnabled);

        coefficient->setText(QString::number(row + 1));

        QTableWidgetItem *sigma = new QTableWidgetItem();

        sigma->setFlags(Qt::ItemIsSelectable | Qt::ItemIsEditable | Qt::ItemIsEnabled);

        sigma->setText("0.0");

      table->setItem(row, columnCount - 1, sigma);

    }

        table->setItem(row, 3, sigma);

    // { NONE: N/A, POSITION: 0, VELOCITY: 1, ACCELERATION: 2, ALL: 2 }

        // Solve option: spk degree -> { NONE: -1, POSITION: 0, VELOCITY: 1, ACCELERATION: 2, ALL: 2 }

        // POSITION

    if (i + 1 > 0) { 

        if (row == 0) { 

          QTableWidgetItem *description = table->item(0, 1);

          description->setText("POSITION");

        }

        // VELOCITY

    if (i + 1 > 1) {

        else if (row == 1) {

          QTableWidgetItem *description = table->item(1, 1);

          description->setText("VELOCITY");

        }

        // ACCELERATION

    if (i + 1 > 2) {

        else if (row == 2) {

          QTableWidgetItem *description = table->item(2, 1);

          description->setText("ACCELERATION");

          QTableWidgetItem *units = table->item(2, 2);

          units->setText("m/s^2");

        }

      }

    }

    table->resizeColumnToContents(1);

    table->resizeColumnToContents(2);