Create all tables ad InnoDB by default

MyISAM isn't properly replicated using row based replication. With the
advances in clustering, these systems are becoming more prevalent and
MyISAM isn't up to the task anymore.

OpenSim/Data/MySQL/Resources/IM_Store.migrations

@@ -11,6 +11,6 @@ CREATE TABLE IF NOT EXISTS `im_offline` (
   PRIMARY KEY (`ID`),
   KEY `PrincipalID` (`PrincipalID`),
   KEY `FromID` (`FromID`)
-) ENGINE=MyISAM DEFAULT CHARSET=utf8;
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
 COMMIT;