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.

OpenSim/Data/SQLite/SQLiteAssetData.cs

@@ -56,6 +56,8 @@ namespace OpenSim.Data.SQLite
 
         private SqliteConnection m_conn;
 
+        override public void Dispose() { }
+
         /// <summary>
         /// <list type="bullet">
         /// <item>Initialises AssetData interface</item>