UI ideas for selecting admin boundaries

[andrewtpham]

As a user, I would like to have a stepwise process that lets me select the admin boundary data set that I would like to work with (for example, GADM 2.8). Then specify my sub-boundary within the dataset (admin 0, 1, 2, 3, etc.).

Once selected, the select sub-boundary should be a layer on the map displayed on TolaActivity.

See screenshots.