use the valid layer name as file name on the disk
fix the group member add, use join. Fixes #1717
Merge branch 'master' of https://github.com/GeoNode/geonode
don't trigger save twice in update layers, set correctly the bbox.
remove erroneous MAP_BASELAYERS definition in local_settings.
Merge pull request #1716 from simod/issue-1713

use the valid layer name as file name on the disk, fixes #1713
Merge pull request #1721 from simod/issue-1719

don't trigger save twice in update layers, set correctly the bbox.