Allow Python 2 longs for max recognitions and in other places

[comodoro]

Using six integer_types

[drmfinlay]

Thanks! Shouldn't min also allow long arguments?

There are a few other instances of this in dragonfly which I can fix. Are there any reasons to only allow int arguments?

[drmfinlay]

I've changed the other int type checks I could find with grep. I'll merge this now. Given that longs don't exist in Python 3, I don't see any problem with just using six.integer_types everywhere.