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
if ( value != null )
				{
					for ( int i = 1; i < groups.length; i++ )
					{
						if ( value.equals( groups[i] ) )
						{
							return new Integer( i );
						}
					}
				}
				return new Integer( 0 );
			}
			if ( value == null )
			{
				value = ""; 
			}
			return value;
		}
		public void modify( Object element, String property, Object value )
		{
			if ( element instanceof Item )
			{
				element = ( (Item) element ).getData( );
			}
			try
			{
				if ( COLUMN_NAME.equals( property ) )
				{
					String newName = UIUtil.convertToModelString( (String) value,
							false );