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
* 
	 * @param module
	 *            the root module of the element
	 * 
	 * @return true if it can be transformed, otherwise false.
	 */
	public boolean canTransformToTemplate( Module module )
	{
		if ( this instanceof TemplateElement || ( !canDrop( ) )
				|| ( isContainTamplateElement( ) ) )
			return false;
		IElementDefn templateReportItem = MetaDataDictionary.getInstance( )
				.getElement( ReportDesignConstants.TEMPLATE_REPORT_ITEM );
		IElementDefn templateDataSet = MetaDataDictionary.getInstance( )
				.getElement( ReportDesignConstants.TEMPLATE_DATA_SET );
		if ( getContainer( ) != null )
			return getContainer( ).canContain( module, getContainerSlot( ),
					templateReportItem )
					|| getContainer( ).canContain( module, getContainerSlot( ),
							templateDataSet );
		return true;
	}
	/**
	 * checks if the element contains any sub level element is a template.
	 * 
	 * @return true if contain template element, otherwise return false.
	 */
	private boolean isContainTamplateElement( )
	{
		int slotCount = getDefn( ).getSlotCount( );