Allow customizing the default consistency level

[DanielSmedegaardBuus]

Would be nice to be able to set the default consistency level when you create a new client, in case you'd like something other than QUORUM :)

[jorgebay]

It can be done now, the way to do it is a little rough...

types.consistencies.getDefault = function () { 
  return types.consistencies.one;
};

It would be nice to set the default consistency at client instance level, what do you think?

[DanielSmedegaardBuus]

Oh yeah :D

Only thing about that is you have to assume the code doesn't change or you'll break it. But it definitely does the job :)