Normalization edge case

[emitra17]

Using the normalization key to map a normalization type to an exp file creates a confusing situation when there is also a prop file with the same suffix.

Looks like what currently happens is if you use the syntax normalization = init : data.exp, all columns of simulation suffix data get normalized for all uses. So if you also had a data.prop for something not even appearing in data.exp, it would get normalized.