Named functions with -d switch don't compile

Named functions don't compile when auto-importing prelude with the -d switch.

``` bash
$ echo "function hello\n  1" | livescript -c -d -s
SyntaxError: misplaced function declaration on line 3

$ echo "function hello\n  1" | livescript -c -s
(function(){
  function hello(){
    return 1;
  }
}).call(this);
```
