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
* @see org.eclipse.birt.report.model.api.GroupElementHandle#getModuleHandle()
	 */
	public ModuleHandle getModuleHandle( )
	{
		return (ModuleHandle) module.getHandle( module );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#getCommonProperties()
	 */
	public List getCommonProperties( )
	{
		List minProps = getMinPropDefns( );
		List commonProps = new ArrayList( minProps );
		Iterator iter = minProps.iterator( );
		while ( iter.hasNext( ) )
		{
			PropertyDefn propDefn = (PropertyDefn) iter.next( );
			for ( int i = 0; i < elements.size( ); i++ )
			{
				if ( !( (DesignElementHandle) elements.get( i ) ).getElement( )
						.getPropertyDefns( ).contains( propDefn ) )
				{
					commonProps.remove( propDefn );
					break;
				}
			}
		}
		return Collections.unmodifiableList( commonProps );