awful.widget: abuse new object item system

We do not need this since we store all Lua refs into env table of
objects.

Signed-off-by: Julien Danjou <julien@danjou.info>

lib/awful/widget/taglist.lua.in

@@ -77,11 +77,6 @@ function new(screen, label, buttons)
         end
     end)
     u(screen)
-    -- Free data on tag removal.
-    -- See tasklist to get why this is needed.
-    hooks.tags.register(function (s, tag, action)
-        if action == "remove" then data[tag] = nil end
-    end)
     return w
 end
 

lib/awful/widget/tasklist.lua.in

@@ -74,13 +74,6 @@ function new(label, buttons)
         end
     end)
     u()
-    -- Free data on unmanage.
-    -- You may thing we do not need to clear data[] on unmanage because it's a
-    -- weak-keyed table. But in fact we need, because it's a loop reference
-    -- between data[client] and data[client][i] = button(reference a client in
-    -- the Lua registry) and since the registry and the button() are totally
-    -- unconnected, Lua does not free anything.
-    hooks.unmanage.register(function (c) data[c] = nil end)
     return w
 end