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/api/DesignElementHandle.java
* @param name
	 *            the name of the shared style. If <code>null</code>, then
	 *            the shared style name is cleared.
	 * @throws StyleException
	 *             If the name is not valid, or if this element does not support
	 *             a style.
	 * 
	 * @see #getStyle()
	 */
	public void setStyleName( String name ) throws StyleException
	{
		DesignElement element = getElement( );
		StyleCommand cmd = new StyleCommand( module, element );
		cmd.setStyle( name );
	}
	/**
	 * Sets the shared style element for this element.
	 * 
	 * @param obj
	 *            the shared style. If <code>null</code>, then the shared
	 *            style is cleared.
	 * @throws StyleException
	 *             If this element does not support a style.
	 * @see #getStyle()
	 * 
	 * @deprecated by {@link #setStyle(SharedStyleHandle)}
	 */
	public void setStyleElement( StyleElement obj ) throws StyleException
	{
		DesignElement element = getElement( );