Support for two queries pagination: first paginate only `id` field and then select records by ids

[leschenko]

For pagination in large tables with many columns sometimes we can get better performance with two queries pagination:

1. paginate only with id column

SELECT `products`.id FROM `products` LIMIT 30 OFFSET 30

2. select records by ids

SELECT `products`.* FROM `products` WHERE `products`.`id` IN (1, 2, 3, 4, 5)

It will be nice to have something like large option in paginate method for two queries pagination.

[mislav]

https://github.com/mislav/will_paginate/wiki#limitations