VOSpaceClient throws IllegalStateException for unauthorized calls

[at88mph]

If a user attempts to create a folder or upload a file into a VOSpace to which they are not authorized to do so, the client will throw an IllegalStateException and a 500 Server Error, which is inappropriate.

The server logs from the service that the client was connecting to correctly report the unauthorized error:
PermissionDenied (401): Write permission denied on ...

But the client interprets it as an IllegalStateException.

[pdowler]

This is probably in the VOSpaceAuthorizer (hope so) and should be an AccessControlException (403).

Alternatively, a check for write permission vs anon could be a NotAuthenticatedException (401), which might help a client take action and move forward.