Don't make 'local' and 'filestorage' singletons

The singleton pattern meant that there is only one FileStorage object,
even if you tried to configure multiple with different filenames.  It
also meant that if you happened to have multiple live storage clients,
all correctly using setup_/delete_namespace(), and they were the LocalStorage,
they'd step on each other.  No metaclass, but all of the LocalStorage share
the same class-local _data.