Bug 145021 Enhance the agrregate on option in column binding dialog
1. Check if the expression is aggregate expression by data utility class. 2. If yes, the option is ?all? and group name list 3. if not, the option disabled (or set to none?) if the column binding is in detail row. If the column binding is in group row, the option is ?None? and group name list.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ColumnBindingDialog.java
private static final String CHOICE_NONE = Messages.getString( "ColumnBindingDialog.Choice.None" );
	private static final String LABEL_COLUMN_BINDINGS = Messages.getString( "ColumnBindingDialog.Label.DataSet" ); 
	private static final String WARN_COLUMN_BINDINGS = Messages.getString( "ColumnBingingDialog.Label.Warn" ); 
	
	
	private static final String COLUMN_NAME = Messages.getString( "ColumnBindingDialog.Column.Name" ); 
	private static final String COLUMN_DATATYPE = Messages.getString( "ColumnBindingDialog.Column.DataType" ); 
	private static final String COLUMN_EXPRESSION = Messages.getString( "ColumnBindingDialog.Column.Expression" ); 
	private static final String COLUMN_AGGREGATEON = Messages.getString( "ColumnBindingDialog.Column.AggregateOn" ); 
	private static final String INPUT_PROPMT = Messages.getString( "ColumnBindingDialog.InputPrompt" ); 
	private static final IChoiceSet dataTypeChoiceSet = DesignEngine.getMetaDataDictionary( )
			.getChoiceSet( DesignChoiceConstants.CHOICE_COLUMN_DATA_TYPE );
	private static final IChoice[] dataTypes = dataTypeChoiceSet.getChoices( null );
	private static final String[] dataTypeDisplayNames = ChoiceSetFactory.getDisplayNamefromChoiceSet( dataTypeChoiceSet );
	private boolean canSelect = false;
	private ReportItemHandle inputElement;
	
	
	private TableViewer bindingTable;
	private ExpressionCellEditor expressionCellEditor;
	private String selectedColumnName = null;
	private String NullChoice = null;
	private IStructuredContentProvider contentProvider = new IStructuredContentProvider( ) {
		public void dispose( )
		{
		}
		public void inputChanged( Viewer viewer, Object oldInput,
				Object newInput )
		{
		}