Bug 146481 Name is not necessary for extended element
Steps to reproduce: 1.New a label named "label" in library 2.New a report, extend lib.label Expected result: No name for the extended label Actual result: "label" is added as the name of label in report. It's not reasonable because "Restore Properties" is enabled even without properties change.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/SimpleGroupElementHandle.java
/*
	 * (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;
				}
				if ( DesignElement.NAME_PROP.equals( propName ) )
				{
					for ( Iterator elementIter = elements.iterator( ); elementIter
							.hasNext( ); )
					{
						DesignElementHandle handle = (DesignElementHandle) elementIter