Add support for serializing and deserializing complex data types.

[itsjohncs]

I'm not sure how this will be done yet, but as it stand if you try to serialize a complex data type (one that stores other models within it for example) you will have to do the serialization of the nested objects yourself, same with deserialization. This isn't all that bad really, but it might be good to add in some hooks into the models to allow some postprocessing to occur after deserialization, and some preprocessing before serialization.