Bug 143173 No error for recursive including when exporting a report to a library
Steps to reproduce: 1.New a library named "Lib", add a lable in it 2.New a report, extends Lib.label 3.Export the report, choose target library "Lib" Expected result: Error to warn the recursive including Actual result: The target library includes itself without error
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/util/ModelUtil.java
{
				
				Iterator images = source.getPropertyHandle( Module.IMAGES_PROP )
						.iterator( );
				while ( images.hasNext( ) )
				{
					StructureHandle image = (StructureHandle) images.next( );
					try
					{
						ElementExportUtil.exportStructure( image,
								(LibraryHandle) destination, false );
					}
					catch ( SemanticException e )
					{
						assert false;
					}
				}
				continue;
			}
			else
				value = propHandle.getElement( ).getStrategy( )
						.getPropertyExceptRomDefault( propHandle.getModule( ),
								propHandle.getElement( ), propDefn );
			Object valueToSet = ModelUtil.copyValue( propHandle.getDefn( ),
					value );
			destination.getElement( ).setProperty( propName, valueToSet );
		}
	}
	/**
	 * Duplicates the extension identifier. The extension identifier must be set