cutData add ability for multiple values

[lmickes]

cutData allows for only one value. How about extending it to include more than one?

[stewartboogert]

So now it is possible to select and keep multiple different values. So the value needs to be a list. The old code (which will still work) looked like this

d = pyWitness.DataRaw("./filename.csv")
d.cutData("author", "author1", "keep")

if multiple values need to be kept it is now

d = pyWitness.DataRaw("./filename.csv")
d.cutData("author", ["author1", "author2"], "keep")

This will not work with the cut option as cut can be called multiple times and typically on different columns

d = pyWitness.DataRaw("./filename.csv")
d.cutData("author", "author1", "cut")
d.cutData("author", "author2","cut")