Clear separation of the count functions/one count function for all

[edegeyer]

To me it didn't seem very obvious to me, that it only counts the UP votes if no parameter is given.
The Code snippet I'm talking about is the following:

    def count(self, action=UP):
        return self.through.votes_for(self.model,
                                      self.instance, action).count()

My suggestion would be, to introduce 2 new functions:
count_up(self)
and
count_down(self)

I would still keep the count function, but modify it in a way, that leads to it counting the up and down votes, by just calling the two other functions and returning them as a dict to the caller