Honor limit and offset in FeedView (bug 1048567)

r? @ngokevin @robhudson
There are `api_settings.PAGINATE_BY + 1` items, so by not passing it uses the default value for it, and I make sure that there are `api_settings.PAGINATE_BY` items (L1239) and that `api_settings.PAGINATE_BY` is the limit returned (L1238).