[NTG-context] [ orientation= -90 != 270 ]

using the \externalfigure option orientation i noticed a difference between orientation=-90 orientation=270 whereas orientation=90 orientation=-270 are identical (as they should) \starttext \startcombination[4 * 2] {\externalfigure[top.jpg][width=40mm, orientation=0]}{0} {\externalfigure[top.jpg][width=40mm, orientation=90]}{90} {\externalfigure[top.jpg][width=40mm, orientation=180]}{180} {\externalfigure[top.jpg][width=40mm, orientation=270]}{270} {\externalfigure[top.jpg][width=40mm, orientation=0]}{0} {\externalfigure[top.jpg][width=40mm, orientation=-90]}{-90} {\externalfigure[top.jpg][width=40mm, orientation=-180]}{-180} {\externalfigure[top.jpg][width=40mm, orientation=-270]}{-270} \stopcombination