fix frame order some more

- Closes #29
Reintroduces UI scale issues when playing at 1080p pixel-perfect (0.711 scale).
You need to account for this by adjusting the Aura size slightly up or down by a small number, depending on scaling.
We have this anyway across the addon, so it is what it is...

WeakAuras/SubRegionTypes/Background.lua

@@ -37,6 +37,9 @@ do
   end
 
   local function subSetFrameLevel(self, level)
+    if self.parent.fgFrame then
+      self.parent.fgFrame:SetFrameLevel(level)
+    end
     if self.parent.bar then
       self.parent.bar:SetFrameLevel(level)
     end