Disable and unregister some FolksDummy.PersonaStores.
For each of the persona stores in stores, disable it (if it was enabled) and unregister it from the backend so that it 
            cannot be re-enabled using Folks.Backend.enable_persona_store or 
              Folks.Backend.set_persona_stores.
Folks.Backend.persona_store_removed will be emitted for all persona stores in stores which were 
            previously enabled. After all removal signals are emitted, a change notification for 
              Folks.Backend.persona_stores will be emitted (but only if at least one removal signal is emitted).
0.9.7