Add back TrackingParticle Selector to digitization.  Change pT threshold to 100 MeV, widen eta acceptance to +/-5
Merged 71X_Mixing_add_TrackingParticle_Selector from repository mdhildreth
Change stableOnly default back to False as per Andrea
Merge pull request #2964 from mdhildreth/71X_Mixing_add_TrackingParticle_Selector

Add back TrackingParticle Selector to digitization.  Change pT threshold...