moved debug option to proof_display.ML (again); normalized Proof.context/method type aliases;
moved debug option to proof_display.ML (again);
normalized Proof.context/method type aliases;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle