New camelize filter #77

I think as default should be the classic javascript `camelCase`, and for special case like `MyAngularController` we can have a different parameter.
E.g.
```js
equal(camelize('test_string')).toBe('testString');
equal(camelize('test_string', true)).toBe('TestString');
```
as html
```html
<p ng-bind="word | camelize"></p>
<p ng-bind="word | camelize:true"></p>
```

What do you think about it?