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/elements/ExtendedItem.java
return provider.getExtensionProperty( prop.getName( ) );
		return null;
	}
	/**
	 * Sets the value of a property. The value must have already been validated,
	 * and must be of the correct type for the property. The property must be
	 * valid for this object. The property can be a system, user-defined
	 * property and a property from the extended element of this item. The value
	 * is set locally. If the value is null, then the property is "unset."
	 * 
	 * @see org.eclipse.birt.report.model.core.DesignElement#setProperty(org.eclipse.birt.report.model.metadata.ElementPropertyDefn,
	 *      java.lang.Object)
	 */
	public void setProperty( ElementPropertyDefn prop, Object value )
	{
		assert prop != null;
		if ( !prop.isExtended( ) )
			super.setProperty( prop, value );
		else if ( provider != null )
			provider.setExtensionProperty( prop, value );
	}
	/**
	 * Gets the property data for either a system-defined, user-defined property
	 * or extension property from extended element of this item.
	 * 
	 * @see org.eclipse.birt.report.model.core.DesignElement#getPropertyDefn(java.lang.String)
	 */
	public ElementPropertyDefn getPropertyDefn( String propName )
	{
		assert propName != null;