Merge proces, enable signing of the assembly.

Frameworks/MQTTnet.NetStandard/ApplicationMessagePublisherExtensions.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Threading.Tasks;
+
+namespace MQTTnet
+{
+    public static class ApplicationMessagePublisherExtensions
+    {
+        public static Task PublishAsync(this IApplicationMessagePublisher client, params MqttApplicationMessage[] applicationMessages)
+        {
+            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));
+
+            return client.PublishAsync(applicationMessages);
+        }
+    }
+}