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
PROPERTY_MASKS_PROP );
		if ( propMasks != null )
		{
			ListIterator masks = propMasks.listIterator( );
			while ( masks.hasNext( ) )
			{
				PropertyMask mask = (PropertyMask) masks.next( );
				errors.addAll( mask.validate( module, this ) );
			}
		}
		return errors;
	}
	/**
	 * Checks all structures in the specific property whose type is structure
	 * list property type. This method is used for element semantic check. The
	 * error is kept in the report design's error list.
	 * 
	 * @param module
	 *            the module
	 * @param propName
	 *            the name of the structure list type
	 * @return the list of the errors found in validation, each of which is the
	 *         <code>SemanticException</code> object.
	 */
	protected List validateStructureList( Module module, String propName )
	{
		return StructureListValidator.getInstance( ).validate( module, this,
				propName );
	}
	/**