Refactor OUTPUT-SYMBOL
- fold both OUTPUT-SYMBOL-NAME and OUTPUT-QUOTED-SYMBOL-NAME into
a new function OUTPUT-SYMBOL* (which could rightly be named
"output-possibly-package-qualified-symbol")
- get rid of MAYBE-QUOTE confusion, since it was true only when called
from OUTPUT-SYMBOL when neither readability nor escaping is wanted.
So just do the right thing in OUTPUT-SYMBOL and call the non-quoting
output function chosen by CHOOSE-SYMBOL-OUT-FUN.
- give the structure printing mechanism a different interface
for printing a non-keyword as if it were a keyword.
- remove some multiple lookups of special vars