Remove `View:extend` override

Call directly `core.register_view(name, class)` to register a `View`. 
The `registered_name` field will be populated automatically.

data/core/docview.lua

@@ -7,10 +7,12 @@ local translate = require "core.doc.translate"
 local View = require "core.view"
 
 
-local DocView = View:extend("DocView")
+local DocView = View:extend()
 
 DocView.context = "session"
 
+core.register_view("doc", DocView)
+
 
 function DocView:get_content()
   return {

data/core/init.lua

@@ -39,6 +39,7 @@ end
 local registered_views = { }
 function core.register_view(name, class)
   registered_views[name] = class
+  class.registered_name = name
 end
 
 function core.get_registered_view(name)

data/core/view.lua

@@ -8,17 +8,6 @@ local Object = require "core.object"
 local View = Object:extend()
 
 
--- Override how objects are created. This allows for automatic Views registration
-function View:extend(register_name)
-  local new_class = View.super.extend(self)
-  if register_name then
-    new_class.registered_name = register_name
-    core.register_view(register_name, new_class)
-  end
-  return new_class
-end
-
-
 -- context can be "application" or "session". The instance of objects
 -- with context "session" will be closed when a project session is
 -- terminated. The context "application" is for functional UI elements.