Sort seed traders by nearness

[Skud]

If I am logged in to Growstuff, when I look at a crop page and seeds are available for trade, they should be sorted in order of geographical closeness.

If I'm logged out, there should be a message saying "Sign in or sign up to see seed traders near you."

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.