facilitate discovery of duplicates

[ralfhauser]

1. make a mouse-over that gives a hint (object ID or alike) to see how the duplicates can be held apart or rather amener au merge

[mmmatthew]

Interesting Idea. The duplicate detection should be implemented on the datablue side. For example:
before merging OSM and Wikidata together, apply a similarity analysis and label possible duplicates. Duplicates can be documented like the merge_notes property.

Blocked until duplicate detection is done: water-fountains/datablue#26