Straighten up api

`fields` parameter is a comma separated list, the API will return only those that are present in the returned object. An additional `_id` field is added too.

`limit` or `size` (default 10 when `page_no` is present) is an int defining number of items to return

`from` or `offset` an int defining how many items to skip before returning the results, starts with 1

`page_no` an int defining page to start returning results from, 1 actually means "return w/o skipping anything"