Fix the "relationship already exists" problem

RTorchia

This behavior has been around awhile, but it really needs to be treated like a bug and fixed.

Here's the steps leading up to the problem (i.e. this isn't the bug, this is what sets up the condition where it's a problem):

1. Start with two profiles, say "Person One" who is married to "Spouse" and has several children, and "Person Two".
2. Merge Person Two into Person One (by mistake, though it hasn't been realized yet).
3. Edit the merged profile. This will cause the "unmerge" to be no longer available -- only "restore".
4. Restore the incorrectly-merged Person Two profile. Now all the sources and relationships are attached to both profiles. (As are the Notes and Discussions, Memories, Other Info, etc. All that stuff will have to be removed manually, which you could also call a bug, but ignore that for now.)
5. Since you want to revert it to the pre-merge state, remove Person Two from the family.

So basically these steps have created a situation where all these children are attached to "Person One" and "Spouse", and are also just attached to "Spouse" alone, as if those are two different sets of parents.

We should be able to add Person One as the father and that should just combine them all back into one family. Instead, when you try to do that, you get an error saying the process failed because the relationship already exists.

There's absolutely no reason that shouldn't just work. It should just ignore that the relationship already exists and and coalesce it back down to one set of parents. The user is clearly just trying to get rid of having only one parent listed.

The workarounds for this are obnoxious. Either you have to detach the children one-by-one from Spouse or you have to create a temporary profile as the other parent and then merge that back into Person One -- fixing a bad merge by merging a fake person.