Code to handle tracking modules in a semi-flexible, semi-intelligent way.
Make a list of sensitive detectors that are active for the current run in ::ConstructAll(), and copy this to EventAction to get rid of annoying warning messages on every event-->GEANT4 bug workaround
Merge branch 'g4sbsv2' of https://github.com/JeffersonLab/g4sbs into g4sbsv2

Conflicts:
	src/G4SBSEventAction.cc
	src/G4SBSHArmBuilder.cc