Add Japanese translation (including spec)
Simplify existing translation files
Prefer self.send(attribute) to read/write_attribute method. There are a number of reasons for this:
1) Mongoid allows aliased field names (so DB field is different than rails attribute alias)
2) There are a number of plugins which operate after the read_attribute method, for example field encryption.
Merge pull request #35 from johnnyshields/master

Better attribute accessor pattern + Japanese translation (sorry for the delay.. missed the request somehow).