Add modular configuration for Robust connectors

We can provide modular ini for connectors...

    look for our configuration in the following places...
      1) in the default ini/-inifile
      2) in the named file (ConfigName) located in the configured directory
            (see Robust[.HG].ini [Start] section for ConfigDirectory)
      3) in the repository named in the connector (ConfigURL)
           In this case, the file will be written into the configured
           directory with the specified

  See example connector/service @ https://github.com/BlueWall/SlipStream
  for testing.

OpenSim/Server/Base/ServicesServerBase.cs

@@ -64,6 +64,12 @@ namespace OpenSim.Server.Base
             get { return m_Config; }
         }
 
+        public string ConfigDirectory
+        {
+            get;
+            private set;
+        }
+
         // Run flag
         //
         private bool m_Running = true;
@@ -153,6 +159,8 @@ namespace OpenSim.Server.Base
                 startupConfig = m_Config.Configs["Startup"];
             }
 
+            ConfigDirectory = startupConfig.GetString("ConfigDirectory", ".");
+
             prompt = startupConfig.GetString("Prompt", prompt);
 
             // Allow derived classes to load config before the console is