Merge pull request #1527 from dagar/Werror

turn on -Werror and fix resulting errors

src/modules/commander/commander.cpp

@@ -268,7 +268,7 @@ int commander_main(int argc, char *argv[])
 					     SCHED_PRIORITY_MAX - 40,
 					     3200,
 					     commander_thread_main,
-					     (argv) ? (const char **)&argv[2] : (const char **)NULL);
+					     (argv) ? (char * const *)&argv[2] : (char * const *)NULL);
 
 		while (!thread_running) {
 			usleep(200);