Updated with changes to Spoofax.
For now, just go with the generated pretty printer instead of the customized one. The customized one needs to be updated every time the grammar changes which is very tedious.
Grammar (.sdf3): support for optional nodelabels AND operators. Name binding (.nab): updated with changed signatures.
These transformation are now no longer needed: because of the changes to the grammar, the signature of the AST now corresponds to the signature of the metamodel.
Because the AST and the metamodel now have the same signature, the transformation from model-to-tree also doesn't require much customization anymore (also see previous commit).
make it even simpler