[JS] Turn off 'latedef' restriction in JSHint

Explanation with examples here: http://jslinterrors.com/option-jshint-latedef

This disables core & safe behavior of function hoisting in JS. From the example, "Because declarations in JavaScript are hoisted to the top of the scope in which they occur it is perfectly safe to reference them earlier." By disallowing function hoisting, we would have to use variable assignment solely to avoid hoisting errors in situations like the following:

```javascript
// hoisting is safe and native, not an antipattern, but will error with latedef to true
function foo() {
  bar();
}

function bar() {
  foo();
}

// would have to do this more procedural, limiting pattern instead
var foo, bar;
foo = function () { /* ... */ };
bar = function () { /* ... */ };
```
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