Refactor Inheritance Hierarchy

[blakewatters]

The current hierarchy is crowded and doesn't provide clear singular responsibilities for each table controller. Split the classes into:

RKTableController (Abstract Superclass)
RKStaticTableController (Used for building static tables, uses RKTableSection and RKTableRow models)
RKNetworkTableController (A subclass of RKStaticTableController that layers on network loading)
RKFetchedResultsTableController (Provides a Core Data backed fetched results controller with network synchronization)

See issue from main RestKit repository: RestKit/RestKit#765