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
public Object[] getElements( Object inputElement )
		{
			List elementsList = getBindingList( (DesignElementHandle) inputElement );
			elementsList.add( dummyChoice );
			return elementsList.toArray( );
		}
	};
	private ITableLabelProvider labelProvider = new ITableLabelProvider( ) {
		public Image getColumnImage( Object element, int columnIndex )
		{
			return null;
		}
		public String getColumnText( Object element, int columnIndex )
		{
			if ( element == dummyChoice )
			{
				if ( columnIndex == 1 )
				{
					return INPUT_PROPMT;
				}
				return ""; 
			}
			ComputedColumnHandle handle = ( (ComputedColumnHandle) element );
			String text = null;
			switch ( columnIndex )
			{
				case 1 :
					text = handle.getName( );
					break;
				case 2 :