Bug 136241 [regression]Preview template in web viewer and pdf didn't get correct effect.
Description: Preview template items in web viewer and pdf didn't get correct effect. Steps to reproduce: 1. Create template items. 2. Preview in Web Viewer and pdf. Expected result: Same effect as in html. Actual result: In web viewer, see only blank box. In pdf, blank page.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ContentCommand.java
ExtendsCommand childCmd = new ExtendsCommand( module, child );
			childCmd.setExtendsElement( parent );
		}
	}
	/**
	 * Adjusts references to an element that is to be deleted. The element to be
	 * deleted is one that has references in the form of element reference
	 * properties on other elements. These other elements, called "clients",
	 * each contain a property of type element reference and that property
	 * refers to this element. Each reference is recorded with a "back pointer"
	 * from the referenced element to the client. That back pointer has both a
	 * pointer to the client element, and the property within that element that
	 * holds the reference. There are two algorithms to handle this reference
	 * property, which can be selected by <code>unresolveReference</code>. If
	 * <code>unresolveReference</code> is <code>true</code>, the reference
	 * property is unresolved. Otherwise, it's cleared.
	 * 
	 * @param referred
	 *            the element to be deleted
	 * @param unresolveReference
	 *            the flag indicating the reference property should be
	 *            unresolved, instead of cleared
	 * @throws SemanticException
	 *             if an error occurs, but the operation should not fail under
	 *             normal conditions
	 * 
	 * @see #adjustReferredClients(DesignElement)
	 */
	private void adjustReferenceClients( ReferenceableElement referred,
			boolean unresolveReference ) throws SemanticException