Changed single-line blocks to be acceptable.

I think single-line blocks are great, and I use them all the time. They're very readable -- more so than braced-single-statement blocks, in my opinion -- and I don't think they're "dangerous" in the Crockford sense, because if it's on a single line it's obvious what's part of the block and what isn't.

For example, I think it's pretty clear in the following that `console.log` will always be called:

```javascript
var volume = 10;
if(louder) volume = 11;
console.log(volume);
```

On the other hand, I *do* think that multi-line blocks without braces are dangerous. For example, this is very confusing:

```javascript
var volume = 10;
if(louder)
  volume = 12;
  console.log(volume);
```

So I left multi-line blocks as needing curly braces.