Making the zone names used on admin related templates consistent with what's being used for the front-end (e.g. Header, Meta, Actions, Content, Sidebar)

--HG--
branch : dev

src/Orchard.Web/Modules/Orchard.Widgets/Views/Items/Widget.Edit.cshtml

@@ -1,9 +1,10 @@
 <div class="sections">
     <div class="primary">
-        @Display(Model.Primary)
+        @Display(Model.Content)
     </div>
     <div class="secondary">
-        @Display(Model.Secondary)
+        @Display(Model.Sidebar)
+        @* todo: (heskew) remove when the CommonPart is adding the save button *@
         <fieldset>
             <input class="button primaryAction" type="submit" name="submit.Save" value="@T("Save")"/>
         </fieldset>