Bug 211703 Support muti-view on report item.
As title described.
xtab/org.eclipse.birt.report.item.crosstab.core/src/org/eclipse/birt/report/item/crosstab/core/de/CrosstabReportItemHandle.java
dimensionView = findDimension( COLUMN_AXIS_TYPE, name );
		if ( dimensionView != null )
			return dimensionView;
		return null;
	}
	/**
	 * Gets the row/column dimension view that refers a cube dimension element
	 * with the given name. The axis type can be either
	 * <code>ICrosstabConstants.ROW_AXIS_TYPE</code> or
	 * <code>ICrosstabConstants.COLUMN_AXIS_TYPE</code>.
	 * 
	 * @param axisType
	 *            row/column axis type
	 * @param name
	 *            name of the cube dimension element
	 * @return
	 */
	private DimensionViewHandle findDimension( int axisType, String name )
	{
		CrosstabViewHandle crosstabView = getCrosstabView( axisType );
		return crosstabView == null ? null : crosstabView.getDimension( name );
	}
	/**
	 * Gets the row/column dimension with the given index. The axis type can be
	 * either <code>ICrosstabConstants.ROW_AXIS_TYPE</code> or
	 * <code>ICrosstabConstants.COLUMN_AXIS_TYPE</code>. And index is 0-based
	 * integer.
	 * 
	 * @param axisType
	 *            row/column axis type