Bug 207564 Column sorting based on data type
Only string sorting happens when a column is selected in preview result page of DataSet Editor irrespective of type of data shown in that column. I'd like to be able to sort the data based on its datatype when a column is selected.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
* 
	 * @throws BirtException
	 */
	public DataSetViewData[] populateAllCachedMetaData(
			DataSetHandle dataSetHandle, DataRequestSession session )
			throws BirtException
	{
		IResultMetaData metaData = session.getDataSetMetaData( dataSetHandle,
				true );
		DataSetViewData[] items = new DataSetViewData[metaData.getColumnCount( )];
		for ( int i = 0; i < metaData.getColumnCount( ); i++ )
		{
			items[i] = new DataSetViewData( );
			items[i].setName( metaData.getColumnName( i + 1 ) );
			items[i].setDataTypeName( metaData.getColumnTypeName( i + 1 ) );
			items[i].setAlias( metaData.getColumnAlias( i + 1 ) );
			items[i].setComputedColumn( metaData.isComputedColumn( i + 1 ) );
			items[i].setPosition( i + 1 );
			items[i].setDataType( metaData.getColumnType( i + 1 ) );
		}
		return items;
	}
	
	/**
	 * update the columns of the DataSetHandle and put the new DataSetViewData[] into htColumns
	 * 
	 * @param dataSet
	 * @param dsItemModel
	 */
	public void updateColumnsOfDataSetHandle( DataSetHandle dataSet,