v42: 
- include files are now all located in *.hh
- cerenkov detector can now tilted and shifted in myRun.mac
- cerenkov material in myRun.mac: 
      air : no cerenkov light produced
   quartz :    cerenkov light produced
- activated tracking only for primary electrons (QweakSimTrackingAction)
 
This is the error message when I run v42 for a while, tracks got stuck in collimator #2:

./QweakSimG4  myRun.mac > /dev/zero
WARNING - G4Navigator::ComputeStep()
          Track stuck, not moving for 10 steps
          in volume -CollimatorHousing- at point (115.199616,748.08945,-3400.898358)
          direction: (-0.1016909357,-0.2322986508,0.9673139565).
          Potential geometry or navigation problem !
          Trying pushing it of 9e-10 mm ...
Killed