Bug 146761 All structure properties change can't be restore
Steps to reproduce: 1.New a report, extends lib.table 2.Add a structure property(such as filter, column binding...) on table 3.Choose the table, click "Restore Property" Expected result: Local propery is removed Actual result: Local property can't be removed so that "Restore Property" is always enabled
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/SimpleGroupElementHandle.java
return false;
		}
		
		
		return !needHide( propName );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#clearLocalProperties()
	 */
	public void clearLocalProperties( ) throws SemanticException
	{
		ActivityStack stack = module.getActivityStack( );
		stack.startTrans( );
		try
		{
			Iterator iter = propertyIterator( );
			while ( iter.hasNext( ) )
			{
				GroupPropertyHandle propHandle = (GroupPropertyHandle) iter
						.next( );
				String propName = propHandle.getPropertyDefn( ).getName( );
				if ( DesignElement.EXTENDS_PROP.equals( propName )
						|| IExtendedItemModel.EXTENSION_NAME_PROP
								.equals( propName ) )
				{
					
					continue;
				}