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
*/
	protected void setIntrinsicProperty( String propName, Object value )
	{
		if ( propName.equals( NAME_PROP ) )
		{
			setName( (String) value );
		}
		else if ( propName.equals( EXTENDS_PROP ) )
		{
			assert getDefn( ).canExtend( );
			assert !( value instanceof ElementRefValue );
			if ( value == null || value instanceof DesignElement )
				setExtendsElement( (DesignElement) value );
			else
				setExtendsName( (String) value );
		}
		else
		{
			assert false;
		}
	}
	/**
	 * 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 name must
	 * also be valid for this object. The name can represent a system or
	 * user-defined property. The value is set locally. If the value is null,
	 * then the property is "unset."
	 * <p>
	 * Part of: Property value system.
	 *