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
}
	/**
	 * Returns the property definition list that has the minimum size.
	 * 
	 * @return the property definition list that has the minimum size.
	 */
	private List getMinPropDefns( )
	{
		int min = Integer.MAX_VALUE;
		List rtnPropDefns = Collections.EMPTY_LIST;
		for ( int j = 0; j < elements.size( ); j++ )
		{
			Object item = elements.get( j );
			if ( !( item instanceof DesignElementHandle ) )
				return Collections.EMPTY_LIST;
			List propDefns = ( (DesignElementHandle) item ).getElement( )
					.getPropertyDefns( );
			if ( propDefns.size( ) < min )
			{
				min = propDefns.size( );
				rtnPropDefns = propDefns;
			}
		}
		return rtnPropDefns;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#isSameType()
	 */