Bastien Montagne
887d052e56
T62570 and T61796 show that we need two slightly different behaviors in post-linking collection process: * For linking, we never want to instantiate indirectly-linked collections or objects. * For appending however, since all collections and objects will become local and hence need instantiation, we want to 'link to scene' all collections first, better than instantiating the objects in the master collection opf current scene.