Bug 145698 Name change won't enable "restore property" button
Steps to reproduce: 1.New a report, extends lib.label 2.Choose the label, switch to property editor, chang its name to "aa" 3.Choose the label again Expected result: "Restore property" button is enabled Actual result: "Restore property" button is grayed out
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/GroupElementHandle.java
* are considered of same type if their element definitions are identical.
	 * <p>
	 * If elements have different definitions. Even the same element type, the
	 * return value is <code>false</code>. For example, if the list contains
	 * an <code>OdaDataSource</code> and a <code>OdaDataSource</code>, this
	 * method returns <code>false</code>.
	 * 
	 * @return <code>true</code> if the given elements are of the same type;
	 *         return <code>false</code> if elements are of different element
	 *         types, or the given list is empty, or the list contains any
	 *         object that is not an instance of
	 *         <code>DesignElementHandle</code>.
	 */
	abstract public boolean isSameType( );
	/**
	 * Returns the common properties shared by the given group of
	 * elements(including user properties). Contents of the list is element
	 * property definitions. If elements do not share any common property,
	 * return an empty list.
	 * 
	 * @return the common properties shared by the given group of elements. If
	 *         elements do not share any common property, or the given list is
	 *         empty, or the list contains any item that is not an instance of
	 *         <code>DesignElementHandle</code>, return an empty list.
	 */
	abstract public List getCommonProperties( );
	/**
	 * Returns an iterator over the common properties. Contents of the iterator
	 * are handles to the common properties, type of them is
	 * <code>GroupPropertyHandle</code>. Note: remove is not support for the