[WIP] Support of disputed_by and claimed_by

[frodrigo]

Try to implement #13

Add disputed_by and claimed_by to the output.

The idea is to have the alternative boundaries accepted by countries and rejected by countries.

[pnorman]

If I understand the docs, this is building a semicolon separated list out of information from multiple relations? Why not create an array?

[frodrigo]

You are right, for direct use within Postgres array are better.

Switching to array.

[frodrigo]

I make an user diary on osm.org about this https://www.openstreetmap.org/user/frodrigo/diary/390502

[pnorman]

Let me know when you're done making changes and it's ready for final review. I still need to run tests/etc.

[frodrigo]

I am still unsure about the approach and the tags.

Nevertheless you can look at the others issues/pull request, there can be validated independently of this pull request.