systray, dock, icon_handler some major revision

awesome/theme/crylia/widgets/date.lua

@@ -54,7 +54,7 @@ return function ()
         shape = function (cr, width, height)
             gears.shape.rounded_rect(cr, width, height, 5)
         end,
-        widget = wibox.widget.background
+        widget = wibox.container.background
     }
 
     local set_date = function ()
@@ -89,4 +89,4 @@ return function ()
     )
 
     return date_widget
-end
+end