Fixed @throws hint

`\LogicException => \PHPCR\RepositoryException`

It's a real BC break but only in docblock.
What about introduce `UnauthenticatedException`?
as all methods except those that say so explicitly require to be logged in, we could explain that behaviour in the interface doc block rather than on each method imho. and remove the "if not logged in" exception line from all interfaces in this folder.