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 ( value == null )
				continue;
			ReferenceValue refValue = (ReferenceValue) value;
			refValue.setLibraryNamespace( nameSpace );
		}
		IElementDefn defn = content.getDefn( );
		for ( int i = 0; i < defn.getSlotCount( ); i++ )
		{
			ContainerSlot slot = content.getSlot( i );
			if ( slot != null )
				for ( int pos = 0; pos < slot.getCount( ); pos++ )
					reviseNameSpace( module, slot.getContent( pos ), nameSpace );
		}
	}
	/**
	 * Determines whether there is a child in the given element, which is kind
	 * of the given element definition.
	 * 
	 * @param element
	 *            the element to find
	 * @param defn
	 *            the element definition type
	 * @return true if there is a child in the element whose type is the given
	 *         definition, otherwise false
	 */
	public static boolean containElement( DesignElement element,
			IElementDefn defn )
	{
		if ( element == null || defn == null )
			return false;