Added simple forms, like loop/list that accumulates bodies into a list.
Add :final that works like in racket:
(loop/list ((:for a (in-list '(1 2 3))) :final (= a 2)) (display a))
=> (1 2)
I have racketified goof loops. No :for or :acc needed, and :when, :unless, and :break are no longer parethesised.
:acc blah (in ...) and :for blah (in ...) has been changed to
(blah (folding ...)) and (blah (in ...))
