Add comparator argument in filterBy [Suggestion]

Hi,
it would be nice if filterBy accepted a comparator like angular's filterFilter (see docs at https://docs.angularjs.org/api/ng/filter/filter). Especially being able to pass "true" to use angular.equals would be handy.

Reason: See plnkr: http://plnkr.co/edit/2PaG9wqRK8V0GWH5hkWl?p=preview Having ids 10,11,12 all return when filtering by 1. We need exact search. :-) I could use filterFilter for this example, but in complex cases, when filterBy comes handy this would be super-cool.