Trying to play with birks constant

I want to setup a simulation to find the best Birks Constant that fits
the measured data.
Trying without a unit

Trying to get the birks parameter without using any of the units.
Added a readme to LightValdiation
Initial Commit of Birks Constant

Searching for the best Birks constant
Saving birks

I don't think I want this anymore.
Fixed minor compile errors
Merge branch 'LightVal' of https://github.com/murffer/DetectorSim into LightVal
Merge branch 'LightVal' of https://github.com/murffer/DetectorSim into LightVal
Fixed the geometry error

Fixed the geometry error!
Optional MPI Added

Optional MPI use was added as a compile directive, and the README was
updated to reflect this.
Updated default histo name
Updated macros
Added job submission script
Changed units on output
Fixed incorrect MPI Precompiler setting

I actually didn't set the MPI flags, and was just compiling with the MPI
libaries.  The flags have now been set in the CMakeLists.txt
A cleanup script for cluster runs
Finished search for Birks

Finished the search for the Birks coefficient for GS20, settled at 0.025
mm/MeV matched the measured spectra pretty well.