Make statements use a cons list for internal representation, and make eval evaluate a cons list

[Bravotic]

Right now we evaluate strings, that should be converted to use a cons list as follows:

(+ 4 (+ 5 6)) -> (cons '+
                       (cons 4
                             (cons (cons '+
                                         (cons 5
                                               (cons 6  
                                                     '())))
                                   '())))

[Bravotic]

This will deprecate every current eval function. Move the functionality of CRO_innerEval into CRO_eval, and determine how to handle strings and files from there.