Created FDModelProvider.
First phase of implementing FDModelProvider.

This is the start of a process that is designed to make FDModel a
standalone component that can be pulled out into its own repo.

The end goal is that FDModel does not need to only be used only through
FDDataClient. In theory someone could want to create instances of
FDModel from NSDictionary objects themselves or from data fetched from
a database.
Added debug helper methods to FDModel.

It has been difficulty debugging how a property for a FDModel is being
parsed by putting in breakpoints because the method that does the
transformation is recursive and so the breakpoints would be triggered
multiple times.

These helper methods allow you to implement them on the FDModel you are
trying to debug and put in breakpoints that will then only trigger on
that specific model.
Performed a pass on all the documentation to ensure it is up to date after the addition of FDModelProvider.