systray, dock, icon_handler some major revision

awesome/theme/crylia/widgets/power.lua

@@ -47,7 +47,7 @@ return function ()
         shape = function (cr, width, height)
             gears.shape.rounded_rect(cr, height, width, 5)
         end,
-        widget = wibox.widget.background
+        widget = wibox.container.background
     }
 
     -- Signals
@@ -61,4 +61,4 @@ return function ()
     )
 
     return power_widget
-end
+end