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/util/ModelUtil.java
* 
	 * @param element
	 *            the element to find
	 * @param defn
	 *            the element definition type
	 * @return true if there is a child in the element whose type is the given
	 *         definition, otherwise false
	 */
	public static boolean containElement( DesignElement element,
			IElementDefn defn )
	{
		if ( element == null || defn == null )
			return false;
		
		int count = element.getDefn( ).getSlotCount( );
		for ( int i = 0; i < count; i++ )
		{
			Iterator iter = element.getSlot( i ).iterator( );
			while ( iter.hasNext( ) )
			{
				DesignElement e = (DesignElement) iter.next( );
				IElementDefn targetDefn = e.getDefn( );
				if ( defn.isKindOf( targetDefn ) )
					return true;
				if ( containElement( e, defn ) )
					return true;
			}
		}
		return false;
	}