Notification of complete tiles for validators

[aawiseman]

John Whelan mentioned this on the HOT email list. I presume he means an opt-in kind of thing where you can check a box that says "notify me when squares are completed"

Some sort of notification of when a tile is completed on a selected project.

Currently I open up four projects each day and check for completed tiles so I can validate them. Three are moving very slowly currently, it can be a couple of weeks before another batch of tiles gets done.

Problem is at the moment the HOT tile server is overloaded and checking for done tiles is a load that really shouldn't be placed on the server unless a tile has been completed.

[aawiseman]

oops, i see it's a duplicate of #933