generic attributes; added low-level modifiers from Pure/context_rules.ML;
generic attributes;
added low-level modifiers from Pure/context_rules.ML;

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