MXS-2264: Fix table versioning

The table versions are now stored in memory and are only resolved on
startup. This simplifies things and removes the need to know where the
data is stored as that information is not available to the Rpl class.

server/modules/routing/avrorouter/avro_rbr.cc

@@ -836,6 +836,7 @@ bool Rpl::save_and_replace_table_create(STableCreateEvent created)
         }
     }
 
+    created->version = ++m_versions[created->id()];
     m_created_tables[table_ident] = created;
     mxb_assert(created->columns.size() > 0);
     return m_handler->create_table(created);