WIP: Format SwitchStatement. Fix for #42

Currently adds indent.SwitchStatement, whiteSpace.*.SwitchDiscriminantOpening and whiteSpace.*.SwitchDiscriminantClosing.

Has various issues with nested statements and comments.

To illustrate those issues:

Input/expected:

```js
call(function(){
    switch (fruit) {
        // case comment
        case Fruit.APPLE:
            // consequent comment
            exotic();
            break;
        default:
            unknown();
    }
});
```

Output/actual, based on the code in this PR:

```js
call(function(){
    switch (fruit) {
    // case comment
        case Fruit.APPLE:
    // consequent comment
                exotic();
                break;
        default:
                unknown();
    }
});
```

The consequents are indented on level too much, the comments indentation is broken.

I'm won't be able to work on this for a while, so I'm sharing what I have so far.