quote a name in an error message
attempt to add a little more information

to help diagnose this (and related) failures:

http://drdr.racket-lang.org/27793/pkgs/drracket-pkgs/drracket-test/tests/drracket/easter-egg.rkt
clean up mistakes in 21807d3

- remove bogus test case
- fix bug in collector
- fix bug in test