Added the ability to register a new plugin by passing an instance of the plugin

Author: niemyjski

Source/Shared/Configuration/ExceptionlessConfiguration.cs

@@ -225,6 +225,16 @@ public IEnumerable<PluginRegistration> Plugins {
             get { return _plugins.Values.OrderBy(e => e.Priority).ToList(); }
         }
 
+        /// <summary>
+        /// Register an plugin to be used in this configuration.
+        /// </summary>
+        /// <typeparam name="T">The plugin type to be added.</typeparam>
+        /// <param name="plugin">The plugin instance to be added.</param>
+        public void AddPlugin<T>(T plugin) where T : IEventPlugin {
+            string key = typeof(T).FullName;
+            _plugins[key] = new PluginRegistration(key, GetPriority(typeof(T)), new Lazy<IEventPlugin>(() => plugin));
+        }
+
         /// <summary>
         /// Register an plugin to be used in this configuration.
         /// </summary>