less verbose debugging
evaluator

Fix apply -- did not recursively evaluate in reducing
lambda args.
evaluator

booleans are self-evaluating.
evaluator

if form evaluates.
environments

Reduced line noise by stripping down __repr__ of
global frame.
builtins

Funny typo.
builtins

Add relational stuff.
evaluator

cond and begin special forms.
Also fix if special form for non-alternative case.