Make the default anonymous identity configurable
At present, the default identity is AnonymousIdentity, if no identity can be loaded.
However it may be the case that an application might want a custom anonymous identity class (e.g. with some default attributes). There is no way at present to handle this.
I would suggest perhaps a signal or decorator that allows you to set the anonymous identity instance. By default of course the current AnonymousIdentity instance would be used.