Ensure that function expressions with ids bind their id inside.

Per https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope:

> (With a function expression,) The function name can be used only
> within the function's body. Attempting to use it outside the
> function's body results in an error (or undefined if the function name
> was previously declared via a var statement).
Merge pull request #33 from eventualbuddha/fix-scope-of-fn-expr-with-id

Ensure that function expressions with ids bind their id inside.