Bug 176436 Charts Imported from Libraries do not update when libraries change
During a live presentation of BIRT at EclipseCon, we came across a rather embarassing issue. When charts are included in a library, and imported into a report design from a library, any changes to the library instance of the chart do not reflect in the report itself.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/GroupPropertyHandle.java
* @return <code>true</code> if this property is an extension defined
	 *         xml property, <code>false</code> otherwise.
	 */
	boolean isExtensionXMLProperty( )
	{
		for ( Iterator iter = handle.getElements( ).iterator( ); iter.hasNext( ); )
		{
			DesignElementHandle elemHandle = (DesignElementHandle) iter.next( );
			if ( elemHandle instanceof ExtendedItemHandle
					&& ( (ExtendedItem) elemHandle.getElement( ) )
							.isExtensionXMLProperty( propDefn.getName( ) ) )
				return true;
		}
		return false;
	}
	/**
	 * Returns the element reference value list if the property is element
	 * referenceable type. The list of available elements are sorted by their
	 * names lexicographically.
	 * 
	 * @return list of the reference element value.
	 */
	public List getReferenceableElementList( )
	{
		List elements = handle.getElements( );
		if ( elements == null || elements.isEmpty( ) )
			return Collections.EMPTY_LIST;
		DesignElementHandle element = (DesignElementHandle) elements.get( 0 );
		PropertyHandle propHandle = element.getPropertyHandle( propDefn
				.getName( ) );