Remove Screen.parent hack in Attachment and Note

The modified test in Screen.switch_view can be moved to
Screen.default_row_activate only, so the Attachment and Note screen doesn't
require to have a fake parent to switch views.

issue5558
review23131002

src/screen.js

@@ -702,9 +702,6 @@
         },
         switch_view: function(view_type) {
             if (this.current_view) {
-                if (!this.group.parent && this.modified()) {
-                    return jQuery.when();
-                }
                 this.current_view.set_value();
                 if (this.current_record &&
                         !~this.current_record.group.indexOf(
@@ -960,7 +957,9 @@
                     'ids': [this.get_id()]
                     }, jQuery.extend({}, this.context), false);
             } else {
-                this.switch_view('form');
+                if (!this.modified()) {
+                    this.switch_view('form');
+                }
             }
         },
         get_id: function() {

src/window.js

@@ -393,7 +393,6 @@
             });
             screen.switch_view().done(function() {
                 screen.search_filter();
-                screen.group.parent = record;
             });
             Sao.Window.Attachment._super.init.call(this, screen, this.callback,
                 {view_type: 'tree'});
@@ -427,7 +426,6 @@
             });
             screen.switch_view().done(function() {
                 screen.search_filter();
-                screen.group.parent = record;
             });
             Sao.Window.Note._super.init.call(this, screen, this.callback,
                     {view_type: 'tree'});