Bug 136973 Refresh problem-column name in chart builder
Description: Use flat file datasource, if change the column name in flat file, the column name will changed in data explorer but not refreshed in chart builder accordingly. Only restart Eclipse will get the correct information.
data/org.eclipse.birt.report.data.adapter/src/org/eclipse/birt/report/data/adapter/impl/QueryExecutionHelper.java
/**
	 * 
	 * @param queryDefn
	 * @param paramBindingIt
	 * @param filterIt
	 * @param bindingIt
	 * @return
	 * @throws BirtException
	 */
	IQueryResults executeQuery( QueryDefinition queryDefn,
			Iterator paramBindingIt, Iterator filterIt, Iterator bindingIt )
			throws BirtException
	{
		defineDataSourceDataSet( queryDefn );
		populateQueryDefn( queryDefn, paramBindingIt, filterIt, bindingIt );
		return dataEngine.prepare( queryDefn ).execute( null );
	}
	/**
	 * @param queryDefn
	 * @throws AdapterException
	 * @throws BirtException
	 */
	private void defineDataSourceDataSet( QueryDefinition queryDefn )
			throws AdapterException, BirtException
	{
		String dataSetName = queryDefn.getDataSetName( );
		List l = this.moduleHandle.getAllDataSets( );
		DataSetHandle handle = null;
		for ( int i = 0; i < l.size( ); i++ )
		{