Simplified

This simplifies how the helpers are used to create a composition system for app code to use.

An `{{#intl}}` block is used to setup a the `data.intl` which will propagate through all helpers and partials. Once setup, the `{{intlNumber}}`, `{{intlDate}}`, and `{{intlMessage}}` helpers can be used and they don't need to be concerned with setting up `locales`.

```html
{{#intl locales=intl.locale messages=intl.messages}}
    <p>
        {{intlMessage intlName="USERS_BOOKS"
            firstName=user.firstName lastName=user.lastName
            numBooks=user.numBooks dateBooks=user.dateBooks}}
    </p>

    <p>{{intlMessage "The number is: {num, number, integer}" num=2000}}</p>

    <p>{{inltNumber 1000 style="currency" currency="USD"}}</p>
{{/intl}}
```

### Todos:

- [x] Update https://github.com/ericf/full-intl integration project
- [x] Update tests to make them pass
- [ ] Update docs to make them accurate