Add ASMScaleManager, which is a singleton that will coordinate between the various scale service providers and clients of this library.
Add a -displayName method to the scale service provider protocol and add a basic implementation of it to the Withings service provider.
Update the example app to use the new scale manager to register the withings provider and retrieve and use the list of registered providers in the top table view.
Disable warnings about implicit sign conversion and sign comparison in the example project so the table view data source and delegate don't need to be cluttered up with casts between indexPaths, array indexes, and array sizes.
Update to the example project storyboard to use a dynamic table for the service provider list instead of static cells.
Service providers must report what class they use to represent users (so the manager can retrieve the appropriate service provider for a given user - this design may change as it is a little weird).
Start fleshing out ASMWithingUser
It's "Withings" not "Withing"