This is broken, because thread locals are not "actor local", so every single task will grab its own UUID block, defeating the sort of pooling that the UUID code was designed to do.

The real solution is to have `Celluloid::Thread` override methods like `#[]` and `#[]=` making them actor local instead of fiber (or TaskThread) local. This should fix a lot of the pain people using gems that use thread locals (e.g. ActiveRecord, MongoMapper)

I would say, for the time being, Celluloid::Thread should just have attr_accessors for these things like the core_ext used to.