Bug 164070 Support widows/orphans properties on text item
Support widows/orphans properties on block text item(label, text, data etc), About the definition of widows/orphans, please refer to CSS spec.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/api/DesignElementHandleTest.java
* </tr>
 * <tr>
 * <td></td>
 * <td>Gets the display label of a label.</td>
 * <td>Display labels of different level match with the design file.</td>
 * </tr>
 * <tr>
 * <td>testPropertyMethods</td>
 * <td>Sets and gets the property value in different set/get property methods.
 * </td>
 * <td>The value can be set and gotten correctly.</td>
 * </tr>
 * <tr>
 * <td>testPropertyMethods</td>
 * <td>Sets and gets the invalid property value.</td>
 * <td>Throws <code>PropertyValueException</code>.</td>
 * </tr>
 * 
 * <tr>
 * <td>{@link #testCanContain()}</td>
 * <td>Whether the label can be contained in the page slot.</td>
 * <td>The return value is false.</td>
 * </tr>
 * 
 * <tr>
 * <td></td>
 * <td>Whether the page can be contained in the page slot before and after
 * inserting in the slot.</td>
 * <td>The return value is true before inserting. The value is false after
 * inserting.</td>