Allow same user to add multiple links as possible duplicates
When seeing a dupe question, I sometimes come up with more than one duplicate to close it with. In other cases, I hastily vote to close as "Not a real question" or "Not constructive" before realizing I could just look up a dupe instead.
In both of these cases, I can no longer suggest a duplicate. That's by design because I can't cast a second vote - makes sense, of course. However, if I could suggest additional dupes without them actually casting another vote,
- the "possible duplicate of" comment would be auto-generated for me
- the dupe I identified will show up in the closing dialog for other users who still have their vote