Scripting: ability to turn on Lua commands style replication globally.

Currently this feature is only accessible via DEBUG for testing, since
otherwise depending on the instance configuration a given script works
or is broken, which is against the Redis philosophy.

src/server.c

@@ -1512,6 +1512,7 @@ void initServerConfig(void) {
     server.lua_time_limit = LUA_SCRIPT_TIME_LIMIT;
     server.lua_client = NULL;
     server.lua_timedout = 0;
+    server.lua_always_replicate_commands = 0; /* Only DEBUG can change it. */
     server.migrate_cached_sockets = dictCreate(&migrateCacheDictType,NULL);
     server.next_client_id = 1; /* Client IDs, start from 1 .*/
     server.loading_process_events_interval_bytes = (1024*1024*2);