New &rest handling.
Typed lambda.
Make define-method typed.
More typechecking.
error handling for unwrap
Combine tests
Split into separate files, joined by browserify.

Write stdlib in s-expression syntax.
Build wat-noparser.js
Add exec bytecode API call.
Fix ignore.
&rest -> .
Update API: use wat.vm() instead of new wat.VM().
Implement push_root_prompt with --push-prompt