geoadmin/mf-geoadmin3 — pull request #232 by cedricmoullet (2013-08-12 19:19:48+00:00)
Title: Add an empty layer

I'm happy to hear feedback about this PR.
This fixes https://github.com/geoadmin/mf-geoadmin3/issues/182
In this PR, the void layer is not really a layer. It removes simply the other background layers. I expect issues when we'll add overlay layers, since index 0 of the layer collection can be a background layer or a normal layer. Any idea how to overcome that ?