Some discrete measures do not interpolate the boundaries for risk groups

[woofwoofola]

Some discrete measures such as avgPPV, avgNPV, avgLRp and avgLRn do not interpolate the group boundaries, but a warning is given that the closest boundaries matching instances are used instead. This affects risk groups, but it does NOT affect demographic groups (which are not interpolated). There is the option to choose the closest boundaries to those specified which avoids this warning and issue. Otherwise, non-interpolated measures will not match interpolated measures. This will be fixed with time.