Make THaDetector.h independent from THaApparatus.h again
Add MCHitInfo::MCClear() function
Add fToF member to MCTrackPoint

This is mostly a convenience variable, like fDeltaE, containing redundant
information which is nevertheless a bit of a pain to calculate interactively.
Remove redundant empty Clear() method. TObject already provides it.
Merge branch 'master' of github.com:/JeffersonLab/analyzer