Update translate_from signature + handling different from_translators

[korikuzma]

The dispatch table approach is pretty clean when each translator has the same arguments, but if we need different params for different translators, I think we probably have to call them within some if/then blocks. A little inelegant but IMO cleaner than passing a bunch of unused arguments to every other function.

Originally posted by @jsstevenson in #148 (comment)