Feature #76: Code reorganization
THaHRS algorithm reorganization
It was a poor design decision to include the s1 and s2 scintillators in the THaHRS spectrometer class. Including the VDC by default is fine, but the scintillators are not really required and not always installed. So, from version 1.6 on, they should be removed.
Also, we should probably create a THaBareHRS or THaHRSBase class without any predefined detectors. This would be useful for checkout of individual detector systems.
Target reconstruction should be moved from the THaVDC class into THaHRSBase. It operates on focal plane tracks regardless of how these tracks are found, so it is not a property of the VDCs, but definitely one of the spectrometer (per its physical construction). THaHRS would then inherit from THaHRSBase.
This issue is related to issue #48 - The THaHRSBase class should implement a MakeTrack method that produces tracks with HRS-style coordinates.