WARNING: BREAKING CHANGES FOR REGION MODULE DEVELOPMENT.

This cleans up Opensim's use of mono addins. In particular, the extension points /OpenSim/RegionModules and /OpenSim/WindModule moved from OpenSim.exe to OpenSim.Region.Framework.dll. From here on, developers of region modules should declare their dlls to be dependent on OpenSim.Region.Framework, starting with version 0.8.1
Additional changes:
- Addins version uniformly updated to 0.8.1. These numbers should be compatible with the release numbers or else it becomes very confusing.
- Mono addins directives moved from files addins.xml to embedded directives in the class and assembly declarations, to make it all consistent

OpenSim/ApplicationPlugins/RemoteController/RemoteAdminPlugin.cs

@@ -39,6 +39,7 @@ using log4net;
 using Nini.Config;
 using Nwc.XmlRpc;
 using OpenMetaverse;
+using Mono.Addins;
 using OpenSim;
 using OpenSim.Framework;
 using OpenSim.Framework.Communications;
@@ -56,6 +57,7 @@ using RegionInfo = OpenSim.Framework.RegionInfo;
 
 namespace OpenSim.ApplicationPlugins.RemoteController
 {
+    [Extension(Path = "/OpenSim/Startup", Id = "LoadRegions", NodeName = "Plugin")]
     public class RemoteAdminPlugin : IApplicationPlugin
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);