- NPS was giving conflict between NP system of Unit and CLHEP one, this is was fixed by a nested ifdef on HEP_SYSTEM_OF_UNIT

* Fixing issue with S1:
 - in Detector Manager a tipo was desabling the condition compilation of S1

* Fixing issue in Isotropic:
 - conflict when the particle was light nuclei given by its name (eg proton instead of 1H)
 - Problem is fixed and user can use gamma, proton, deuton, triton and alpha spelling

   + this allows to remove CLHEP dependency in NPLib
   + this allows to remove Constant.h file

 - Try as an absolute or relative path
 - if fail try in the standard location
 - if fail exit with error code 1

 - Renaming of private member of Initial Condition
 - Beam energy was not set in Read Configuration

 - fixing couple of bug
 - remove some warning
 - enhance performance

 - Only one read configuration file method
 - lighter code
 - possibility to use TH1F for cross section shoot

 - Add associate class in NPL
 - Add Function in NPL

Some code clean up has been done as well (cosmetic change for the most)