New Dynamic Map Option: Full opacity

[Chenier]

Name: Opacity for the dynamic map

Summary:
Either the ability to display no base map, or to display additional layers without at 0% transparency, or a slider to modify the transparency per layer.

Benefits:
Many of the layers on the dynamic map are fairly hard to "read" because of the transparency and color overlap with the regions below them. "Is that region another color because their layer value is different, or because that one's a rural and the other is a badland?", for example. Being able to toggle full opacity (0% transparancy) would allow to better read those layers, and potentially generate interesting looking results for archival.

Downsides:
None other than the time it takes to code.