Put the virtual decls back in, they're needed by the freshly donated ...

... XStorage module that creates the XML for the new viewer, anod more.
It overrides them to know if new init XML needs to be cached.

OpenSim/Data/MySQL/MySQLSimulationData.cs

@@ -62,7 +62,7 @@ namespace OpenSim.Data.MySQL
         /// </summary>
         private object m_dbLock = new object();
 
-        protected Assembly Assembly
+        protected virtual Assembly Assembly
         {
             get { return GetType().Assembly; }
         }
@@ -76,7 +76,7 @@ namespace OpenSim.Data.MySQL
             Initialise(connectionString);
         }
 
-        public void Initialise(string connectionString)
+        public virtual void Initialise(string connectionString)
         {
             m_connectionString = connectionString;