Discovery of storage

While writing tests for Section 4.1, I found no reliable way to discover a storage, and therefore no reliable way to test this section's requirements.

Now, since we generally have a storage on the server's /, for the most part, you could just start with that, and the tests would pass, but that's not the requirement. A server may support several storages, but parts of the URI space doesn't need to be a storage.

In the current protocol, you can discover the storage by traversing towards it's root container. So, in principle, you could GET /foo/bar to discover that the root container is /foo/. However, this can't be used for discovery, because it would require the entire URI space to be covered by storages, and that may not be the case. If I have understood it correctly, you could for example have that /pods/users/foo/ is the root container for the user foo, and similarly for other users. Then, just GET /bar/baz will not yield a pointer to a storage.

To remedy this problem, I suggest that we have a way that clients can discover the pods as a SHOULD level requirement (so that a server may support anonymous pods, but otherwise should make them discoverable).