#129 calsummary reports positive values when tsys is negative

[Anonymous]

calsummary and the plot viewer report positive TSYS values when the real TSYS value is negative. I believe this is because of a squaring operation in calsummary. However, there may be other places where TSYS is set to |TSYS|. This is a problem, because negative TSYS values indicate a problem with the data, but they are hidden from the user.