Fix salinityPP so can ignore depth data <= -5m (reminder: positive downward)
Fix salinityPP so can ignore depth data <= -5m (reminder: positive downward)

ggalibert/imos-toolbox,ggalibert/imos-toolbox,ggalibert/imos-toolbox,ggalibert/imos-toolbox,ggalibert/imos-toolbox