Control, via configuration, which permissions can assigned to certain roles

Permissions need to be configured in sakai.properties:

realm.allowed.roles=anon
realm.allowed..anon=annc.read,poll.vote

The permissions in default.sakai.properties are incorrect. I'll correct them. Until they're set on the nightlies you won't be able to test.

i can give .anon create permission

This was added as part of a previous commit of an Oxford fix. I've just added this ticket as a QA resource - test plan and all that.