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
* 
	 * @throws SemanticException
	 *             If the value cannot be cleared.
	 */
	public void clearValue( ) throws SemanticException
	{
		if ( isExtensionModelProperty( ) )
		{
			ActivityStack actStack = handle.getModule( ).getActivityStack( );
			actStack.startTrans( );
			try
			{
				for ( Iterator iter = handle.getElements( ).iterator( ); iter
						.hasNext( ); )
				{
					DesignElementHandle elemHandle = (DesignElementHandle) iter
							.next( );
					if ( elemHandle instanceof ExtendedItemHandle )
					{
						ExtendedItem parent = (ExtendedItem) elemHandle
								.getElement( ).getExtendsElement( );
						parent.initializeReportItem( parent.getRoot( ) );
						elemHandle.setProperty( propDefn.getName( ), parent
								.getLocalProperty( parent.getRoot( ),
										propDefn ) );
					}
				}
			}
			catch ( SemanticException e )
			{