Re-use open iD window / tab

[mvexel]

We are already re-using an existing open iD tab, so this is not about that.

Here is my use case: I have iD open with custom map overlay, because the Challenge requires that layer to be visible. Specifically, this challenge requires the TIGER roads overlay to be visible. However, when we reload the iD tab for the next task, the overlay disappears and I have to go back into the iD layers menu to re-add it to the visible layers.

@bhousel do you have any suggestions on how to enable this use case?

[bhousel]

Oh yeah adding custom raster overlays is something I need to add support for - I'm tracking it on openstreetmap/iD#3773

[mvexel]

Once that is resolved we should enable this in MapRoulette. Perhaps we can use the Editor Layer Index to populate a list we can serve in the Challenge create screen.