U4-4761 Member translation

Makes all trees translateable, does not break the current titles set on
atttributes, but for trees that does not have a title set, the tree wil
try to look up a treeheader.

src/Umbraco.Web/Trees/MemberTreeController.cs

@@ -27,7 +27,7 @@ namespace Umbraco.Web.Trees
         Constants.Applications.Media,
         Constants.Applications.Members)]
     [LegacyBaseTree(typeof (loadMembers))]
-    [Tree(Constants.Applications.Members, Constants.Trees.Members, "Members")]
+    [Tree(Constants.Applications.Members, Constants.Trees.Members)]
     [PluginController("UmbracoTrees")]
     [CoreTree]
     public class MemberTreeController : TreeController

src/Umbraco.Web/Trees/TreeAttribute.cs

@@ -20,7 +20,7 @@ namespace Umbraco.Web.Trees
         /// <param name="sortOrder">The sort order.</param>
         public TreeAttribute(string appAlias,
             string alias,
-            string title,
+            string title = "",
             string iconClosed = "icon-folder",
             string iconOpen = "icon-folder-open",
             bool initialize = true,

src/Umbraco.Web/Trees/TreeController.cs

@@ -1,8 +1,12 @@
 using System;
 using System.Collections.Concurrent;
+using System.Globalization;
 using System.Linq;
 using System.Net.Http.Formatting;
+using System.Threading;
+using System.Web.Security;
 using Umbraco.Core;
+using Umbraco.Core.Models;
 using Umbraco.Web.Models.Trees;
 using Umbraco.Web.Mvc;
 
@@ -37,7 +41,22 @@ namespace Umbraco.Web.Trees
         /// </summary>
         public override string RootNodeDisplayName
         {
-            get { return _attribute.Title; }
+            get
+            {
+                //if title is defined, return that
+                if(string.IsNullOrEmpty(_attribute.Title) == false)
+                    return _attribute.Title;
+
+
+                //try to look up a tree header matching the tree alias
+                var culture = CultureInfo.GetCultureInfo(Security.CurrentUser.Language.Replace("_", "-"));
+                var localizedLabel = Services.TextService.Localize("treeHeaders/" + _attribute.Alias, culture);
+                if (string.IsNullOrEmpty(localizedLabel) == false)
+                    return localizedLabel;
+
+                //is returned to signal that a label was not found
+                return "[" + _attribute.Alias + "]";
+            }
         }
 
         /// <summary>