Support reindex with to better syntax

Author: Gabriel Moskovicz

src/Nest/ElasticClient-Reindex.cs

@@ -14,5 +14,11 @@ public IObservable<IReindexResponse<T>> Reindex<T>(Func<ReindexDescriptor<T>, Re
 			var observable = new ReindexObservable<T>(this, _connectionSettings, reindexDescriptor);
 			return observable;
 		}
+
+		/// <inheritdoc />
+		public IObservable<IReindexResponse<object>> Reindex(Func<ReindexDescriptor<object>, ReindexDescriptor<object>> reindexSelector)
+		{
+			return Reindex<object>(reindexSelector);
+		}
 	}
 }

src/Nest/IElasticClient.cs

@@ -19,6 +19,12 @@ public interface IElasticClient
 		IObservable<IReindexResponse<T>> Reindex<T>(Func<ReindexDescriptor<T>, ReindexDescriptor<T>> reindexSelector)
 			where T : class;
 
+		/// <summary>
+		/// Helper method that allows you to reindex from one index into another using SCAN and SCROLL.
+		/// </summary>
+		/// <returns>An IObservable you can subscribe to to listen to the progress of the reindexation process</returns>
+		IObservable<IReindexResponse<object>> Reindex(Func<ReindexDescriptor<object>, ReindexDescriptor<object>> reindexSelector);
+
 		/// <summary>
 		/// A search request can be scrolled by specifying the scroll parameter. 
 		/// <para>The scroll parameter is a time value parameter (for example: scroll=5m), 

src/Tests/Nest.Tests.Integration/Index/ReindexTests.cs

@@ -13,7 +13,7 @@ public class ReindexTests : IntegrationTests
 		public void ReindexMinimal()
 		{
 			var toIndex = ElasticsearchConfiguration.NewUniqueIndexName();
-			var observable = this.Client.Reindex<object>(r => r
+			var observable = this.Client.Reindex(r => r
 				.FromIndex(ElasticsearchConfiguration.DefaultIndex)
 				.ToIndex(toIndex)
 			);
@@ -42,7 +42,7 @@ public void ReindexMinimal()
 		public void Reindex()
 		{
 			var toIndex = ElasticsearchConfiguration.NewUniqueIndexName();
-			var observable = this.Client.Reindex<object>(r => r
+			var observable = this.Client.Reindex(r => r
 				.FromIndex(ElasticsearchConfiguration.DefaultIndex)
 				.ToIndex(toIndex)
 				.Query(q=>q.MatchAll())