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
* operations that change an element <strong>must </strong> be made though a
 * command. So, if you find a method <code>setMumble( )</code> that is of
 * interest, you must locate (or create) a <code>SetMumble</code> command to
 * perform this operation in a way that can be undone. Also, some of the
 * operations described here are incomplete, in that they handle a task only on
 * this one element. Many tasks must be done on several elements to be complete.
 * For example, if we call the <code>setExtends( )</code> method of element E,
 * we also must cache the inverse relationships in the parent element. This
 * higher-level semantic processing is handled by code above this class.
 * 
 * <h3>Meta-data</h3>
 * 
 * This class stores information that the user enters for a design element.
 * Every element is defined by an <em>element definition </em>. The
 * relationship between an element and element definition is much like that
 * between a object and a class in Java. The element definition defines
 * characteristics of the element, and is fixed by the development team. The
 * element is defined by the user and contains information needed for a
 * particular report.
 * <p>
 * The {@link #getDefn}method provides access to the element definition for the
 * particular element. The returned {@link ElementDefn}object provides access
 * to the properties defined for the element as well as other information.
 * <p>
 * This abstract base class provides operations common to all (or most)
 * elements. The application creates Java subclasses to represent the various
 * kinds of report elements. Those subclasses provide the behavior specific to
 * that element type, usually allocating space for any element slots and
 * providing a callback into the {@link ElementVisitor design visitor}class.
 * <p>