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
{
		if ( from.getDefn( ).allowsUserProperties( ) )
		{
			Iterator iter = from.getUserProperties( ).iterator( );
			while ( iter.hasNext( ) )
			{
				UserPropertyDefn userPropDefn = (UserPropertyDefn) iter.next( );
				to.addUserPropertyDefn( userPropDefn );
			}
		}
		Iterator iter = from.getDefn( ).getProperties( ).iterator( );
		while ( iter.hasNext( ) )
		{
			ElementPropertyDefn propDefn = (ElementPropertyDefn) iter.next( );
			String propName = propDefn.getName( );
			
			
			
			if ( StyledElement.STYLE_PROP.equals( propName )
					|| DesignElement.EXTENDS_PROP.equals( propName )
					|| DesignElement.USER_PROPERTIES_PROP.equals( propName )
					|| DesignElement.REF_TEMPLATE_PARAMETER_PROP
							.equals( propName ) )
				continue;
			Object localValue = to.getLocalProperty( from.getRoot( ), propDefn );
			Object parentValue = from.getStrategy( ).getPropertyFromElement(
					from.getRoot( ), from, propDefn );
			if ( localValue == null && parentValue != null )
			{
				Object valueToSet = ModelUtil.copyValue( propDefn, parentValue );