Bug 124620 Referenced Parameter icon should be invalid if the parameter in library is deleted
Description: Referenced parameter icon should be invalid if the source parameter in library is deleted. Steps to reproduce: 1.Create a library. Insert a report scalar parameter. 2.Create a report, use the above library. In the library explorer, pull the parameter to the data explorer view of report. 3.Open the library file, delete the parameter. Then reopen the report design file, the icon of parameter seems nothing happened. But if those operations happened in dataset, the icon of dataset in the report will be invalid. It is acceptable. Expected Result: The icon of referenced parameter should be invalid.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
if ( ev.getDeliveryPath( ) != NotificationEvent.STYLE_CLIENT )
				ev.setDeliveryPath( NotificationEvent.DESCENDENT );
			Iterator iter = derived.iterator( );
			while ( iter.hasNext( ) )
			{
				( (DesignElement) iter.next( ) ).broadcast( ev, module );
			}
		}
	}
	/**
	 * Returns <code>true</code> if the element is within a child element
	 * which extends from another. Returns <code>false</code> otherwise. <br>
	 * <strong>Notice: </strong> <br>
	 * If the element is a virtual element, it must have defined a <code>
	 * baseId<code> which point to the ID of its virtual parent. 
	 * 
	 * @return Returns <code>true</code> if the element is within a child element
	 * which extends from another.
	 */
	public final boolean isVirtualElement( )
	{
		return baseId != NO_BASE_ID;
	}
	/**
	 * Copied the structure from the parent element to the element itself. Local
	 * properties of the contents will all be cleared.Please note that the
	 * containment relationship is kept while property values of the content
	 * elements are not copied.