Move type casting and default handling at store level
Allow to not define accessors on the model
Update README
ActiveRecord 4.1 do not require fallback code anymore
Backport ar 4.0 IndifferentCoder for ar 3.2
Encode Marshal serials in Base64 to wrokaround DB issues

See http://stackoverflow.com/questions/1906421/problem-saving-rails-marshal-in-sqlite3-db
Extract store_accessors method