Update ol

This PR updates OpenLayers in the project to the last ol3 master:
https://github.com/openlayers/ol3/commit/8a0809c6730b28023273e4da8fef9ba6dd3af946

I didn't need to change anything in mf-geoadmin3 because ol3 API have not changed (except for some projection stuff we don't use in mf-geoadmin3).

Please review and merge.