[jhc] darcs patch: save gc pointer in evaluator function ra... (and 3 more)

Fri Mar 26 19:12:22 PDT 2010 John Meacham * save gc pointer in evaluator function rather than in eval itself Fri Mar 26 21:45:42 PDT 2010 John Meacham * short circuit redirects in the garbage collector Sat Mar 27 11:50:11 PDT 2010 John Meacham * greatly simplify garbage collection algorithm, trust underlying malloc implementation more. Sat Mar 27 11:59:13 PDT 2010 John Meacham * GC cleanups