Freeze persona changes in the store.
This freezes externally-visible changes to the set of personas in the store until FolksDummy.PersonaStore.thaw_personas_changed is called, at which point all pending changes are made visible in the Folks.PersonaStore.personas property and by emitting Folks.PersonaStore.personas_changed.
Calls to FolksDummy.PersonaStore.freeze_personas_changed and FolksDummy.PersonaStore.thaw_personas_changed must be well -nested. Pending changes will only be committed after the final call to FolksDummy.PersonaStore.thaw_personas_changed.
0.9.7