Make filters more flexible

I would like to see filters get some of the treatments that other Skuid objects have, including:

- The ability to set a class and ID on a filter control
- The ability to control rendering of a filter control

I’d also love to see another filter-like concept where you can sort based on some order by clauses either on a toggle button or a select option, similar to select filters with manual settings.

I’ve been able to implement this functionality (conditional rendering of filters and filters doing sorts) on a queue, but it takes some snippet and CSS trickery to make it happen - so it would be awesome if it were in the core product.

But if anybody needs help making it happen, let me know!  Glad to share the code / concepts.

- Chris