[fractaladl] Make BindingLoader.checkNode accessible to derived classes
In the Cecilia-newmacros toolchains, the component merger retriggers checks and modifications in various Loaders/Checkers. Among those is checking of the binding nodes, done by o.o.f.c.adl.bindings.BindingResolverLoader. Currently, BindingResolverLoader (which extends o.o.f.adl.bindings.TypeBindingLoader which extends o.o.f.adl.bindings.BindingLoader) can't call BindingLoader.checkNode(), because this method is declared private. To achieve our aims, we must therefore resort to dirty tricks such as copying & pasting the code of checkNode into BindingResolverLoader... not good.
BindingLoader.checkNode() should be declared "protected", like all its sibling methods of the same class.