KObj extension stage I/III

KObj extension stage I/III

Isolate the reference counting for kobj classes in special functions to
allow clean locking in the next step.

Merge all calls of kobj_class_compile either into the new
kobj_class_instantiate or into kobj_init and make it static. Same for
kobj_class_free.

Remove kobj_class_compile_static, it wasn't used and is pretty pointless
since the kobj framework is not used before the VM subsystem has been
initialized.