Bug 136074 Filter editor needs to support column binding
In the Fitler tab of property editor for table/chart, Expression only shows dataset column, rather than column binding. Since column binding is supported for filter of table/chart, this is supposed to show the column binding.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/views/attributes/providers/FilterModelProvider.java
*            ReportItem object
	 * @return Columns array.
	 */
	private String[] getDataSetColumns( ReportItemHandle handle )
	{
		DataSetHandle dataSet = handle.getDataSet( );
		if ( dataSet == null )
			return EMPTY;
		models = DataSetManager.getCurrentInstance( ).getColumns( dataSet,
				false );
		if ( models == null )
			return EMPTY;
		String[] values = new String[models.length];
		for ( int i = 0; i < models.length; i++ )
		{
			values[i] = models[i].getDisplayName( );
		}
		return values;
	}
	private Object getResultSetColumn( String name )
	{
		if ( models == null )
			return null;
		for ( int i = 0; i < models.length; i++ )
		{
			DataSetItemModel model = models[i];
			if ( model.getDisplayName( ).equals( name ) )
				return model;
		}
		return null;