Bug 119566 Support template items in page header/footer
Currently you can't create template report items inside a page header/footer. This should be fixed.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* <dt><strong>Element type </strong></dt>
 * <dd>Inheritance only works between elements of the same type. One could say
 * that a derived element inherits the element type of the parent element. More
 * precisely, both the parent and derived elements have a type, and the
 * semantics of the application require that the element types be the same. It
 * is an error to extend an element of a different type.</dd>
 * 
 * <dt><strong>User-defined properties </strong></dt>
 * <dd>The user can define a custom property. All derived elements also have
 * that property.</dd>
 * 
 * <dt><strong>Custom behavior </strong></dt>
 * <dd>The user can define custom behavior by associating the element with a
 * Java class. Derived elements inherit this behavior.</dd>
 * </dl>
 * <p>
 * 
 * Inheritance does <em>not</em>, however, apply to the following:
 * <p>
 * <ul>
 * <li><strong>Name </strong>. A derived element does not inherit the name of
 * the parent component. If it did, then there would be two elements with the
 * same name, violating the rules about element name uniqueness.</li>
 * 
 * <li><strong>Parent element </strong>. A derived element necessarily has a
 * distinct value for the "extends" property than does its parent.</li>
 * </ul>
 * <p>
 * 
 * Members and classes in the inheritance system include: