Add Environment Printout

[tvarney]

The project requirements for this are:

The interpreter should build an Environment that prints out like FAE but with lisp/scheme syntax.

This should be simple to do, but the syntax of the environment printout is iffy. Should we go with:

(let ((sym value) ...))

as the full environment printout, or should we attempt to do nesting such as:

(let ((sym value)) (let ((sym value)) ... ))

It would be easier to do the former, and just as correct as the latter.

[tvarney]

This is complete in the most recent master branch. I went with the first syntax, with multiple binding instances in the let.