Particle Gun fix, Updated CKF
Sim changes:
- Fix setting of particle gun parameters so they actually are used
- Create proper uniform phase space sampling over a radius
- Update config files for these changes
Digi changes:
- Create digi/merge script to handle small hits files
Reco changes:
- Merge Tobias CKF2 update
- Set up to use material corrections file (now on cvmfs)
- Write raw tracker hits and MC truth in reco output
- Change waveform timing threshold to 40% (optimal value)