testPhysics.C - Gamma Efficiency Test 

testPhysics.C now works.  It needs to be compiled, an example compile line is included at the top of the file.  It can be run from the command line witha single fragment tree as an argument.  It has the following functions:
- Loops through built fragments in fragment tree.
- Produce "Crystal" and "Clover Add-back" energy spectra from any TIGRESS fragments in the tree and save these to a root file (testPhysicsOut.root).
- Produce gated spectra for events that were in coincidence with an 1173 keV gamma.  
- Integrates the counts around 1332.5 keV in the gated spectra to calculate the efficiency.
- Dumps efficiency and count information out to terminal.

Still to do:
- Allow a chain of files to be processed together.
- More information in the report at the end and some kind of "This looks good/bad" summary message.