Object associations

[jonathanwestin]

If we have an image of an object, and we also have another image of that particular object, or a 3d model of that object, or a song of that object, we could use the tag system to associate them by giving the same tag... however, tags should really be more general (like vase, king, crocodile and not a particular vase, king or crocodile) so it would be nice to also be able to directly establish connections between objects in the database that the frontend could use to show these related items.