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
{
		private Object container;
		private CellHandle newTarget;
		public LabelAddRule( Object container )
		{
			this.container = container;
		}
		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.birt.report.designer.internal.ui.views.actions.InsertInLayoutAction.InsertInLayoutRule#canInsert()
		 */
		public boolean canInsert( )
		{
			if ( container instanceof SlotHandle )
			{
				container = ( (SlotHandle) container ).getElementHandle( );
			}
			if ( !( container instanceof CellHandle ) )
				return false;
			CellHandle cell = (CellHandle) container;
			
			boolean canInsert = false;
			if ( cell.getContainer( ).getContainer( ) instanceof TableGroupHandle )
			{
				canInsert = true;
			}
			else