DataFrames Compatibility

[jay-dennis]

When using DataFrames, the indirect inference module needs to be modified to re-index the id column for repeated rows. Probably the easiest way to accomplish this is to allow an id column kwarg and add the iteration times the order of magnitude of N to each id. We can do this by adding a "j" column and then overwriting the id column as id + (j-1)*max(id).