Added AutomaticProxyDetection to Connectionconfiguration

So that we can set proxy to nul an avoid Automaticproxudection when
there is nothing to detect, looking for automatic proxy setting can slow
down the first call by 5 seconds.

Author: Christiaan baes

Diff for: src/Elasticsearch.Net/Connection/ConnectionConfiguration.cs

@@ -82,6 +82,9 @@ public class ConnectionConfiguration<T> : IConnectionConfigurationValues, IHideO
 #endif
 		bool IConnectionConfigurationValues.KeepRawResponse { get{ return _keepRawResponse; } }
 
+        private bool _automatixProxyDetection;
+        bool IConnectionConfigurationValues.AutomaticProxyDetection { get { return _automatixProxyDetection} }
+
 		private int _maximumAsyncConnections;
 		int IConnectionConfigurationValues.MaximumAsyncConnections { get{ return _maximumAsyncConnections; } }
 
@@ -290,6 +293,17 @@ public T SetConnectionStatusHandler(Action<IElasticsearchResponse> handler)
 			this._connectionStatusHandler = handler;
 			return (T) this;
 		}
+
+        /// <summary>
+        /// Sometimes automatic proxydection can be very slow when there is no proxy that can be detected.
+        /// </summary>
+        /// <param name="enabled">defaults to true</param>
+        /// <returns></returns>
+        public T AutomatixProxyDetection(bool b = true)
+        {
+            this._automatixProxyDetection = b;
+            return (T)this;
+        }
 	}
 }
 

Diff for: src/Elasticsearch.Net/Connection/HttpConnection.cs

@@ -146,7 +146,10 @@ private void SetProxyIfNeeded(HttpWebRequest myReq)
 				proxy.Credentials = credentials;
 				myReq.Proxy = proxy;
 			}
-			//myReq.Proxy = null;
+            if(!this.ConnectionSettings.AutomatixProxyDetection)
+            {
+                myReq.Proxy = null;
+            }
 		}
 
 		private void SetBasicAuthorizationIfNeeded(HttpWebRequest myReq)

Diff for: src/Elasticsearch.Net/Connection/IConnectionConfiguration.cs

@@ -65,5 +65,12 @@ public interface IConnectionConfiguration<out T> : IHideObjectMembers
 		/// Global callback for every response that NEST receives, useful for custom logging.
 		/// </summary>
 		T SetConnectionStatusHandler(Action<IElasticsearchResponse> handler);
+
+        /// <summary>
+        /// Sometimes automatic proxydection can be very slow when there is no proxy that can be detected.
+        /// </summary>
+        /// <param name="enabled">defaults to true</param>
+        /// <returns></returns>
+        T AutomatixProxyDetection(bool enabled = true)
 	}
 }

Diff for: src/Elasticsearch.Net/Connection/IConnectionConfigurationValues.cs

@@ -24,6 +24,7 @@ public interface IConnectionConfigurationValues
 		bool TraceEnabled { get; }
 		bool UsesPrettyResponses { get; }
 		bool KeepRawResponse { get; }
+        bool AutomaticProxyDetection { get; }
 
 		/// <summary>
 		/// Instead of following a c/go like error checking on response.IsValid always throw an ElasticsearchServerException