Change "Display" setting accept variables

Right now "Display" let's you choose Always, Bright Only, Dim Only, & Never.

With the enhanced LUA abilities recently added, we can add all sorts of flags, and we can use those flags to control "opacity" to decide whether a layer is shown or not, but that leave the layer active, even if not visible. This means layers with Tap ACtions stay active and erfomr the tap action, even if you can't see it.

Adding a way to accept a variable whether to actually display the layer or not would alleviate this problem. Instead of just making a layer invisible, we could actually make it just not be there at all.