Print warning if NatJ creates a binding object based on a super class

[Berstanio]

I had the following issue:
I had a abstract super class A with subclass B and subclass C. Than I had a block callback that got a object of type A as a parameter. But type A was never actually passed, only either B or C.
Than in the callback I had something like:

if (paramA instanceof B) {
     // Do x
} else if (paramA instanceof C) {
    // Do y
}

The problem was now, that I have never referenced class B or C directly, so their static init block with NatJ.register() was never executed.
When now the callback was called NatJ created a binding java object A for the ObjC classes B and C, so my "instanceof" code wasn't working correctly.
It would be probably good to have NatJ print a warning in such cases, something like "No binding class for ObjC class B/C was registered, falling back to superclass binding A".