filter with non-int columns

[Phlya]

If one wants to perform filtering (like > or <) with columns that are not cast to int by default, distiller fails, because there is no -t argument passed to pairtools select. Not sure whether this is possible to do automatically, but would be good to find a way.
E.g. this needed to be added to the filter command in order to use algn_ref_span:
-t algn_ref_span1 int -t algn_ref_span2 int