I tried to sort on some various docvalues fields (just byte arrays), a few problems:
- Sort.TYPE.BYTES always throws an exception (its not in the switch?)
- only Sort.TYPE String,Float,Int actually honor 'useDocValues'. This is pretty screwy,
why don't the others? at least we should throw an exception and don't try to uninvert something.
In general i dont like the useDocValues: I think this should be done another way...