LED matrix display - MD_Parola, MD_MAX72xx and MD_MAXPanel

If one set of female headers is replaced with female right angle headers,
http://www.karlssonrobotics.com/cart/6-pin-right-angle-female-header/?gclid=CLyetIbV2LcCFYyY4Aodsj8AWQ
then adjacent boards can be plugged together.