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/DataSetMetaDataHelper.java
QueryDefinition query = new QueryDefinition( );
		query.setDataSetName( dataSetName );
		query.setMaxRows( 1 );
		return new QueryExecutionHelper( dataEngine, modelAdaptor, moduleHandle ).executeQuery( query,
				null,
				null,
				null )
				.getResultMetaData( );
	}
	/**
	 * 
	 * @param dataSetHandle
	 * @return
	 * @throws BirtException
	 */
	IResultMetaData refreshMetaData( DataSetHandle dataSetHandle )
			throws BirtException
	{
		IResultMetaData rsMeta = null;
		BirtException e = null;
		try
		{
			rsMeta = this.getDataSetMetaData( dataSetHandle, false );
		}
		catch ( BirtException e1 )
		{
			e = e1;
		}
		if ( needsSetCachedMetaData( dataSetHandle, rsMeta ) )
		{