Comparisons.

Equality and orderings, lists only have equality for now.
Implement if primitive.
car, cdr & cons.

We have *a lisp*!
cond.

Only kind-of a special from, you must quote your clauses yourself
because we don't have macros yet and we can implement `cond` if we have
`if`, so I just did that.
No else clause and all tests failing returns nil (`'()`).
Add simple version of eval (quote stuff yourself).
Simple `case` form, escape yourself, evals results.
Quick! Make a repl!
Add a Makefile for easier invocation/playing time.
Aaand now with an environment (and set! and define).

`cond` is broken, though.
User-defined functions.
Add io functions.
Add a (somewhat) standard library.

Also know as "semi-random grabbag of fun/useful functions".