Bug 123406 Add geLocaltStringProperty in GroupElementHandle and GroupPropertyHandle
Please refer to 123405. GUI need a way to get the local setting of given property because current getStringPropery method will return inherited value if there are no local value.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/SimpleGroupElementHandle.java
* 
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#isPropertyVisible(java.lang.String)
	 */
	protected boolean isPropertyVisible( String propName )
	{
		List elements = getElements( );
		for ( int i = 0; i < elements.size( ); i++ )
		{
			PropertyHandle propertyHandle = ( (DesignElementHandle) elements
					.get( i ) ).getPropertyHandle( propName );
			
			
			
			if ( propertyHandle != null && !propertyHandle.isVisible( )
					|| propertyHandle == null )
				return false;
		}
		
		
		return !isInvalidInMasterPage( propName );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#clearLocalProperties()
	 */
	public void clearLocalProperties( ) throws SemanticException
	{
		ActivityStack stack = module.getActivityStack( );
		stack.startTrans( );