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
* iterator.
	 * 
	 * @return an iterator over the common properties. Contents of the iterator
	 *         are handles to the common properties, type of them is
	 *         <code>GroupPropertyHandle</code>
	 */
	public final Iterator propertyIterator( )
	{
		return new GroupPropertyIterator( getCommonProperties( ) );
	}
	/**
	 * Returns an iterator over the common properties that are visible. Contents
	 * of the iterator are handles to the common properties, type of them is
	 * <code>GroupPropertyHandle</code>. Note: remove is not support for the
	 * iterator.
	 * 
	 * @return an iterator over the common properties. Contents of the iterator
	 *         are handles to the common properties, type of them is
	 *         <code>GroupPropertyHandle</code>
	 */
	abstract public Iterator visiblePropertyIterator( );
	/**
	 * Checks whether a property is visible in the property sheet. The visible
	 * property is visible in all <code>elements</code>.
	 * 
	 * @param propName
	 *            the property name
	 * @return <code>true</code> if it is visible. Otherwise
	 *         <code>false</code>.
	 */