Mantis#1591. Thank you graciously, Sempuki for a patch that:

Currently module loading is done ad-hoc. I propose creating a simple 
loader class that leverages Mono.Addins (and perhaps the new .NET 
addins when they become available in mono). Attached is a basic 
patch for review that compiles into HEAD, but doesn't yet replace 
any existing ad-hoc loaders.

4 files changed, 132 insertions, 5 deletions

diff --git a/OpenSim/Framework/IAssetProvider.cs b/OpenSim/Framework/IAssetProvider.cs
index 5c02ff1..dcb79ea 100644
--- a/OpenSim/Framework/IAssetProvider.cs
+++ b/OpenSim/Framework/IAssetProvider.cs
@@ -38,4 +38,4 @@ namespace OpenSim.Framework
         void CommitAssets(); // force a sync to the database
         void Initialise(string connect);
     }
-}
\ No newline at end of file
+}
diff --git a/OpenSim/Framework/IPlugin.cs b/OpenSim/Framework/IPlugin.cs
index 8a0b2b1..342918c 100644
--- a/OpenSim/Framework/IPlugin.cs
+++ b/OpenSim/Framework/IPlugin.cs
@@ -25,12 +25,24 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+using System;
+
 namespace OpenSim.Framework
 {
     /// <summary>
+    /// Exception thrown if Initialise has been called, but failed.
+    /// </summary>
+    public class PluginNotInitialisedException : Exception
+    {
+        public PluginNotInitialisedException () : base() {}
+        public PluginNotInitialisedException (string msg) : base(msg) {}
+        public PluginNotInitialisedException (string msg, Exception e) : base(msg, e) {}
+    }
+
+    /// <summary>
     /// This interface, describes a generic plugin
     /// </summary>
-    public interface IPlugin
+    public interface IPlugin : System.IDisposable
     {
         /// <summary>
         /// Returns the plugin version
@@ -45,8 +57,8 @@ namespace OpenSim.Framework
         string Name { get; }
 
         /// <summary>
-        /// Initialises the plugin (artificial constructor)
+        /// Default-initialises the plugin
         /// </summary>
         void Initialise();
     }
-}
\ No newline at end of file
+}
diff --git a/OpenSim/Framework/PluginLoader.cs b/OpenSim/Framework/PluginLoader.cs
new file mode 100644
index 0000000..26df3d1
--- /dev/null
+++ b/OpenSim/Framework/PluginLoader.cs
@@ -0,0 +1,115 @@
+/*

+ * Copyright (c) Contributors, http://opensimulator.org/

+ * See CONTRIBUTORS.TXT for a full list of copyright holders.

+ *

+ * Redistribution and use in source and binary forms, with or without

+ * modification, are permitted provided that the following conditions are met:

+ *     * Redistributions of source code must retain the above copyright

+ *       notice, this list of conditions and the following disclaimer.

+ *     * Redistributions in binary form must reproduce the above copyright

+ *       notice, this list of conditions and the following disclaimer in the

+ *       documentation and/or other materials provided with the distribution.

+ *     * Neither the name of the OpenSim Project nor the

+ *       names of its contributors may be used to endorse or promote products

+ *       derived from this software without specific prior written permission.

+ *

+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY

+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY

+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+ */

+

+using System;

+using System.IO;

+using System.Collections.Generic;

+using System.Reflection;

+using log4net;

+using Mono.Addins;

+

+namespace OpenSim.Framework

+{

+    public class PluginLoader <T> : IDisposable where T : IPlugin

+    {

+        private static readonly ILog log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

+        private List<T> loaded = new List<T>();

+

+        public PluginLoader (string dir)

+        {            

+            AddPluginDir (dir);

+        }

+

+        public void AddPluginDir (string dir)

+        {

+            suppress_console_output_ (true);

+            AddinManager.Initialize (dir);

+            suppress_console_output_ (false);

+        }

+

+        public delegate void Initialiser (IPlugin p);

+        private void default_initialiser_ (IPlugin p) { p.Initialise(); }

+

+        public void Load (string extpoint)

+        {

+            Load (extpoint, default_initialiser_);

+        }

+

+        public void Load (string extpoint, Initialiser initialize)

+        {

+            AddinManager.Registry.Update (null);

+

+            ExtensionNodeList ns = AddinManager.GetExtensionNodes(extpoint);

+            foreach (TypeExtensionNode n in ns)

+            {

+                T p = (T) n.CreateInstance();

+                initialize (p);

+                Plugins.Add (p);

+

+                log.Info("[PLUGINS]: Loading plugin " + n.Path + "/" + p.Name);

+            }

+        }

+

+        public List<T> Plugins

+        {

+            get { return loaded; } 

+        }

+

+        public void Dispose ()

+        {

+            foreach (T p in Plugins)

+                p.Dispose ();

+        }

+

+        public void ClearCache()

+        {

+            // The Mono addin manager (in Mono.Addins.dll version 0.2.0.0) occasionally seems to corrupt its addin cache

+            // Hence, as a temporary solution we'll remove it before each startup

+            if (Directory.Exists("addin-db-000"))

+                Directory.Delete("addin-db-000", true);

+

+            if (Directory.Exists("addin-db-001"))

+                Directory.Delete("addin-db-001", true);

+        }

+

+        private static TextWriter prev_console_;

+        public void suppress_console_output_ (bool save)

+        {

+            if (save)

+            {

+                prev_console_ = System.Console.Out;

+                System.Console.SetOut(new StreamWriter(Stream.Null));

+            }

+            else

+            {

+                if (prev_console_ != null) 

+                    System.Console.SetOut(prev_console_);

+            }

+        }

+

+    }

+}

diff --git a/OpenSim/Framework/Servers/OSHttpRequestPump.cs b/OpenSim/Framework/Servers/OSHttpRequestPump.cs
index 06e41e4..6214ab0 100644
--- a/OpenSim/Framework/Servers/OSHttpRequestPump.cs
+++ b/OpenSim/Framework/Servers/OSHttpRequestPump.cs
@@ -58,4 +58,4 @@ namespace OpenSim.Framework.Servers
             return pumps;
         }
     }
-}
\ No newline at end of file
+}