renamed Isar/isar_output.ML to Thy/thy_output.ML; renamed Isar/term_style.ML to Thy/term_style.ML; renamed Isar/thy_header.ML to Thy/thy_header.ML; added Isar/spec_parse.ML; added Thy/ml_context.ML; load outer_parse.ML early, moved later parts to spec_parse.ML; tuned order;