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/internal/ui/dnd/InsertInLayoutUtil.java
return items != null
					&& items.length > 1
					&& target != null
					&& ( target instanceof DesignElementHandle || target instanceof ListBandProxy );
		}
		/**
		 * 
		 * Returns multiple insert positions in form of array
		 */
		public Object getInsertPosition( )
		{
			Object[] positions = new Object[items.length];
			if ( target instanceof CellHandle )
			{
				CellHandle firstCell = (CellHandle) target;
				TableHandleAdapter tableAdapter = HandleAdapterFactory.getInstance( )
						.getTableHandleAdapter( getTableHandle( firstCell ) );
				int currentColumn = HandleAdapterFactory.getInstance( )
						.getCellHandleAdapter( firstCell )
						.getColumnNumber( );
				int currentRow = HandleAdapterFactory.getInstance( )
						.getCellHandleAdapter( firstCell )
						.getRowNumber( );
				int columnDiff = currentColumn
						+ items.length
						- tableAdapter.getColumnCount( )
						- 1;
				
				if ( columnDiff > 0 )
				{