v1.42.0

-- Fix issue with probe.snirf or any other snirf files with no data or intentionally corrupt data being accepted as valid.
-- Fix Nirs2Snirf not working for some some .nirs datasets which do not have CondNames. Add default CondNames to NirsClass.ErrorCheck()
-- Fix display of mlAct in MainGUI broken after the measurement list order issue.
-- For diagnostic purposes save error code in err field of all the SnirfClass sub-classes
-- Add back to MainGUI making channels invisible by mouse right-clicking on them.