This change tries to infer the attribution given the source configuration of the ol3 object. Apparently each OL3 source type might have different properties for storing the attribution. Thus the code needs to iterate over them and "search" for the presence of it.
WARNING: This also slightly changes the default behavior, meaning while currently the attribution had to be enabled explicitly you now have to opt-out by setting the source.attribution = false.
This change tries to infer the attribution given the source configuration of the ol3 object. Apparently each OL3 source type might have different properties for storing the attribution. Thus the code needs to iterate over them and "search" for the presence of it.
WARNING: This also slightly changes the default behavior, meaning while currently the attribution had to be enabled explicitly you now have to opt-out by setting the
source.attribution = false.