added an alphabet picker to some screens

MediaBrowser.Api/Library/LibraryHelpers.cs

@@ -75,7 +75,7 @@ namespace MediaBrowser.Api.Library
                 throw new DirectoryNotFoundException("The media collection does not exist");
             }
 
-            if (Directory.Exists(newPath))
+            if (!string.Equals(currentPath, newPath, StringComparison.OrdinalIgnoreCase) && Directory.Exists(newPath))
             {
                 throw new ArgumentException("There is already a media collection with the name " + newPath + ".");
             }

MediaBrowser.Api/UserLibrary/ItemsService.cs

@@ -127,6 +127,9 @@ namespace MediaBrowser.Api.UserLibrary
         [ApiMember(Name = "SeriesStatus", Description = "Optional filter by Series Status. Allows multiple, comma delimeted.", IsRequired = false, DataType = "string", ParameterType = "query", Verb = "GET", AllowMultiple = true)]
         public string SeriesStatus { get; set; }
 
+        [ApiMember(Name = "NameStartsWith", Description = "Optional filter whose name begins with a prefix.", IsRequired = false, DataType = "string", ParameterType = "query", Verb = "GET", AllowMultiple = true)]
+        public string NameStartsWith { get; set; }
+
         /// <summary>
         /// Gets or sets the air days.
         /// </summary>
@@ -451,6 +454,11 @@ namespace MediaBrowser.Api.UserLibrary
                 items = items.Where(f => vals.Contains(f.GetType().Name, StringComparer.OrdinalIgnoreCase));
             }
 
+            if (!string.IsNullOrEmpty(request.NameStartsWith))
+            {
+                items = items.Where(i => i.Name.IndexOf(request.NameStartsWith, StringComparison.OrdinalIgnoreCase) == 0);
+            }
+
             // Filter by Series Status
             if (!string.IsNullOrEmpty(request.SeriesStatus))
             {