Style layers in layerlist

[alukach]

A user should be able to control the style of a layer's corresponding geometry within the layerlist.

I'd prefer that they be able to access this control via a menu brought up from a right-click on a layer in the layerlist. The color of the layer would represented in the layerlist (possibly as a 5px border left of the text). The color could also represent whether the state was visible or not (turn to grayscale or something...).

[alukach]

Updating this to pertain to the entire style of the layer. This could include putting the icon representing a point feature into the layerlist.

Additionally, representing visibility of the layer seems unnecessary, as the checkbox does that for us.