Add more Channel and Server constructor overloads

src/csharp/Grpc.Core/Channel.cs

@@ -61,6 +61,17 @@ namespace Grpc.Core
 
         bool shutdownRequested;
 
+        /// <summary>
+        /// Creates a channel that connects to a specific host.
+        /// Port will default to 80 for an unsecure channel and to 443 for a secure channel.
+        /// </summary>
+        /// <param name="target">Target of the channel.</param>
+        /// <param name="credentials">Credentials to secure the channel.</param>
+        public Channel(string target, ChannelCredentials credentials) :
+            this(target, credentials, null)
+        {
+        }
+
         /// <summary>
         /// Creates a channel that connects to a specific host.
         /// Port will default to 80 for an unsecure channel and to 443 for a secure channel.
@@ -68,7 +79,7 @@ namespace Grpc.Core
         /// <param name="target">Target of the channel.</param>
         /// <param name="credentials">Credentials to secure the channel.</param>
         /// <param name="options">Channel options.</param>
-        public Channel(string target, ChannelCredentials credentials, IEnumerable<ChannelOption> options = null)
+        public Channel(string target, ChannelCredentials credentials, IEnumerable<ChannelOption> options)
         {
             this.target = GrpcPreconditions.CheckNotNull(target, "target");
             this.options = CreateOptionsDictionary(options);
@@ -91,6 +102,17 @@ namespace Grpc.Core
             GrpcEnvironment.RegisterChannel(this);
         }
 
+        /// <summary>
+        /// Creates a channel that connects to a specific host and port.
+        /// </summary>
+        /// <param name="host">The name or IP address of the host.</param>
+        /// <param name="port">The port.</param>
+        /// <param name="credentials">Credentials to secure the channel.</param>
+        public Channel(string host, int port, ChannelCredentials credentials) :
+            this(host, port, credentials, null)
+        {
+        }
+
         /// <summary>
         /// Creates a channel that connects to a specific host and port.
         /// </summary>
@@ -98,7 +120,7 @@ namespace Grpc.Core
         /// <param name="port">The port.</param>
         /// <param name="credentials">Credentials to secure the channel.</param>
         /// <param name="options">Channel options.</param>
-        public Channel(string host, int port, ChannelCredentials credentials, IEnumerable<ChannelOption> options = null) :
+        public Channel(string host, int port, ChannelCredentials credentials, IEnumerable<ChannelOption> options) :
             this(string.Format("{0}:{1}", host, port), credentials, options)
         {
         }

src/csharp/Grpc.Core/Server.cs

@@ -67,11 +67,19 @@ namespace Grpc.Core
         bool startRequested;
         volatile bool shutdownRequested;
 
+
+        /// <summary>
+        /// Creates a new server.
+        /// </summary>
+        public Server() : this(null)
+        {
+        }
+
         /// <summary>
-        /// Create a new server.
+        /// Creates a new server.
         /// </summary>
         /// <param name="options">Channel options.</param>
-        public Server(IEnumerable<ChannelOption> options = null)
+        public Server(IEnumerable<ChannelOption> options)
         {
             this.serviceDefinitions = new ServiceDefinitionCollection(this);
             this.ports = new ServerPortCollection(this);