TODO
====

 * implement all Emacs Lisp types/objects

 * relational operators: < > <= >= =

 * boolean operator: not

 * special forms: if, cond, and, or, let, let*, letf, letf*

 * primitives: list/cons functions, string functions,
   	       apply, eval,
               require, provide

 * macros

 * dynamic scoping
 
 * merge with Ymacs?

 * look into CommonJS