Bug 130492 Provide a method to serialize the report with library information.
Currently, when engine generate the report document file, the document does not contain any library information. That will cause many propblem on server side. Model should provide a method to serialize the report with library information to a stream so that the generated report document can contain all information that the report need.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* allowed to extend each other. The following is the terminology used for this
 * system.
 * <ul>
 * <li>If element E extends element D, then D is said to be the
 * <em>parent </em> element, and element E is the <em>derived </em> element.
 * </li>
 * <li>We can also use the term <em>base </em> as a synonym for parent. That
 * is, D is the base element above.</li>
 * <li>Element D may in turn extend another element C.</li>
 * <li>We say that C and D are <em>ancestor </em> elements of E, and that D
 * and E are <em>descendents </em> of C.</li>
 * <li>In this simple hierarchy, element E is the <em>most derived </em>
 * element, while element C is the <em>most base </em> element.</li>
 * </ul>
 * <p>
 * Inheritance applies to the following:
 * <p>
 * <dl>
 * <dt><strong>Property values </strong></dt>
 * <dd>An element inherits any property values defined by any of its ancestors.
 * If two ancestors define values for the same property, then the inherited
 * value is that defined by the most derived ancestor. This rule is similar to
 * the method overriding rules in Java.</dd>
 * 
 * <dt><strong>Named style </strong></dt>
 * <dd>If an ancestor element explicitly names a style, then the derived
 * element will also use that style (unless the derived element specifies a
 * different style.)</dd>
 * 
 * <dt><strong>Element type </strong></dt>