removeStyle helper

There should be a helper for removing style attributes from a set of elements

* Add fixtures (requirejs-text is required)
* Using classes to track which items to use for which tests (may not stick)

**Reviewers:** @scalvert 

#### How to test:
Update tests/runner/main.js manually:

```
            var tests = [
                '../../tests/unit/capitalizeTests.js',
                '../../tests/unit/removeStyleTests.js'
            ];
```
Though this is good, in terms of reducing the set of items, we've actually iterated twice here: once for the filter call, and once for the removeAttr call. Instead, we could iterate once just using

```
return this.removeAttr('style');
```

And it would achieve the same thing, rather than O(n + m).