This PR is related to https://github.com/backdrop-contrib/leaflet/issues/53.
It consists of 3 commits. For my use case of adding multiple WMS overlays, they are all needed.
But generally, they can be applied independently.
First removes a bug that overlays are added as layers.
Second adds a new configuration option for custom map overlays to be enabled by default.
Third adds WMS support.
This PR is related to https://github.com/backdrop-contrib/leaflet/issues/53. It consists of 3 commits. For my use case of adding multiple WMS overlays, they are all needed. But generally, they can be applied independently. First removes a bug that overlays are added as layers. Second adds a new configuration option for custom map overlays to be enabled by default. Third adds WMS support.