Add Moab+Torque to the list of available Scheduler/ressource manager

Since Torque does not have an equivalent of srun, I had to design a solution with pdsh. The code in its current form suppose that the torque module for pdsh is installed. I also refactor the Makefile again to better accommodate addition of scheduler and program to spawn the process on the compute nodes (i.e: srun, pdsh).

For now, I have not created a directory with the moab-torque submit scripts already created, nor modified the README to reflect this addition.

One final note, I was not sure how the *submission type* should be called, so I simply went with the *moabtorque* contraction. If someone has better idea...

And thanks for magpie! It is quite useful.