Document AutoFactory#className and eagerly enforce the contract

[Zubnix]

className property of the AutoFactory should either accept the fully qualified name (preferably, as it name implies) or the javadoc should clearly mention that it is actually the simple classname (current situation which actually limits functionality so not really desired(?)).

[gk5885]

The behavior is WAI. There was a lot of discussion about that and because changing the package has a lot of implications on which visibility modifiers are acceptable, we decided that it was a lot of added complexity for little benefit.

I completely agree about the javadocs though.

[gk5885]

And come to think of it, we should definitely have a good set of checks to ensure that it is a valid identifier with good, useful error messages.