Fix #355: mlaunch should print warning message for invalid options (#501)
Fix #355: mlaunch should print warning message for invalid options (#501)

* Fix #355: mlaunch should print error message for invalid options, rather than silently ignoring
* Fix #356: mlaunch --help should mention it accepts arbitrary mongod/mongos flags, including -f/--config

rueckstiess/mtools,rueckstiess/mtools