Allow to launch N time the same command.

[mgermain]

Add the -d, --duplicate command line argument that will add a #PBS -t 0-4 to give the option to launch duplicate of the same command.

See: http://docs.adaptivecomputing.com/torque/3-0-5/2.1jobsubmission.php#jobarrays

It is also worth investigating if we should manage all jobs batches (with worker) this way.

[mgermain]

PR #122 for feature #109 should allow to do this for now.