openlayers/ol3 — pull request #1943 by elemoine (2014-04-03 14:57:38+00:00)
Title: Hit detection skips layers in invisible groups

This fixes a bug [reported](https://groups.google.com/d/msg/ol3-dev/YWJHcKC6-O8/_ywn8JZdqgsJ) on the mailing list where the hit detection code detects features that are not rendered because their layer's group is invisible.

Please review.