Differences between the real Emacs Lisp and elisp.js.  It might seem
silly to start this at such an early stage but at the same time, why
not start now.  It might help keep a reality check on this project.


No Overflow on Math Ops
=======================

There is no overflow on math operations as the native JavaScript
number type is used.  Emacs uses at least 29 bits and supports
integers from -268,435,456 to 268,435,455.

Emacs: (+ 200000000 200000000) #=> -136870912
       536870913               #=> 1

elisp> (+ 200000000 200000000) #=> ["number", 400000000]
       536870913               #=> ["number", 536870913]