Merge pull request #2 from namin/master

some mutable datastructure tests
added bechmmarking info under full chez
changed answer to answero
updated code in cesk-quines.scm to use answero
updated code in cesk-quines.scm to use make-proco abstraction
reordered goals in apply-proco, with negligible change in performance
reordered goals in variable lookup code, with significant speedup
reordered goals in cesk-quines, with negligible change in performance
added symbolo constraint to apply-proco
apply-ko now abstracts over empty-k
cleaned up variable names
removed benchmark comments
reformatted answers
reformatted answers
reformatted answers
added comments to suspect answers
added comments and improved representation-independence of code
cut the running time in half by reordering conde clauses
made all v-out arguments for values fresh variables, which did not change answers or running time
removed v-out argument from apply-ko, without adverse effects