fixed handling of theorem references such as "foo bar" (with quotes), "foo bar(2)", and "foo bar(2)"(2)
fixed handling of theorem references such as "foo bar" (with quotes), "foo bar(2)", and "foo bar(2)"(2)

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