Add support for not:fhrs:id for when businesses change

[EdLoach]

An example - the address for what was a café now homes a hypnotherapy clinic. Adding support for not:fhrs:id would allow me to associate the id with the property to know I've surveyed it and know it is no longer there, rather than keep revisiting the blue dots to see if it is a new business that needs surveying. At the moment I'm tempted to just add it as fhrs:id to show that the property has been surveyed, even though the business differs, but there are other examples where there are ids for both the current takeaway and the one that precedes it (e.g. http://www.openstreetmap.org/way/115526745 where I now have the id for the current business in the fhrs:id tag and the one for the previous takeaway in not:fhrs:id tag).

I would imagine that with a fairly high turnover of businesses in some areas that semi-colon support for multiple values would also be needed for this tag.

Edit: perhaps old:fhrs:id would be more accurate

[gregrs-uk]

Thanks for this, Ed. I don't think I'll have time to do anything about this in the near future but will have a think about it when I have some more time.

[andrewblack]

I can think of places it would help. E.g. a pub that has changed name then back again - a few cases near us. Might help keep armchair mappers with out of date knowledge at bay.