ToF digitizer usage, transition from ToF Hit Producer

1) New classes

   The TofHitProducerNew object has to be replaced by a CbmTofDigitizerBDF object 
   and a CbmTofSimpClusterizer object. An example of this is in 
   macro/to/digitizer/run_digi.C <= Digitizer only
   macro/to/digitizer/run_reco.C <= Digitizer along with normal reco chain for 
      MVD, STS, TRD and RICH
   
   Additionally an optional test class called CbmTofTests is avaliable if one 
   wants to cross check the good working of the digitizer and the clusterizer.

2) Parameters

   a) Beam data input file: 
      test_bdf_input.root, root script to generate it can be made available 
      by P.-A. Loizeau

   b) Cluster distribution to cluster radius conversion 
      Provide the conversion from Landau Fit on cluster size distribution to 
      Landau parameters for Cluster radiusdistribution: 
      RadToClustDist_0000_1000_0010_00025_05025_00025.root

   c) Digitizer geometry description file (same as HitProd): 
      tof_vXXyyy.digi.par

   d) Digitizer options file: 
      tof.digibdf.par
   e) Clusterizer options file: 
      tof.digibdf.par

   e) Digitizer Options:
      See description of allowed values in the file itself!!!
            General Options
      i)   UseExpDigi: Type of ToF digis to use
      ii)  UseOnlyPrim: Only primaries or all tracks
      iii) UseOneGapPerTrk: Use only 1st fired gap per (Track, Channel) pair
      iv)  ClusterModel: Choose cluster charge distribution model, have effect
              on which adjacent strips fire if the FEE threshold is not 0
      v)   FeeGainSigma, FeeTotThr, TimeResElec: Electronics properties
      vi)  TimeResStart: Start counter resolution
      vii) SignalPropSpeed: Propagation speed along electrode
            Geometry Options
         These options have to match the geometry files!!! 
         For most of them, see the Create_TOF_Geometry_*.C macros in the 
         macro/tof/geometry folder.
         Options iv to viii allow for the creation of SM with mixed RPC types.
      i)    NbSmTypes: How many different type of SM used in this geometry
      ii)   NbSm: Number of SM for each SM type
      iii)  NbRpc: Number of RPC inside a single SM for each SM type
      iv)   NbGapsXXX: Number of gaps for each RPC in a SM of type XXX
      v)    GapSizeXXX: Single gap size for each RPC in a SM of type XXX
      vi)   NbChXXX: Number of channels for each RPC in a SM of type XXX
      vii)  ChTypeXXX: Channel type (strip, pad) for each RPC in a SM of type 
               XXX
      viii) ChOrientationXXX: Channel orientation (vertical, horizontal for 
               each RPC 
               in a SM of type XXX
            Beam data options
         These options are related to how the data from measurements are
      used in the digitizer.
      i)    BeamInputFile: ROOT file containing the test data used to get a 
               "realistic" response. This file contains the RPC resolution, 
               efficiency, cluster size distribution and cluster charge 
               distribution for at least 1 RPC type.
      ii)   ClusterRadiusModel: Model used to generate the radius of each 
               Cluster.
      iii)  SmTypeInpMapp: If more than 1 RPC type test in ROOT file, map them 
               to SM types. Not yet compatible with multiple RPC types per SM.
      iv)   RadiusLandauMpv: Optional, used if ClusterRadiusModel is chosen to 
               be a Landau distribution with user fixed parameters.
      v)    RadLandauSigma: Optional, used if ClusterRadiusModel is chosen to 
               be a Landau distribution with user fixed parameters.
      
   f) Clusterizer Options:
      See description of allowed values in the file itself!!!
      i)   MulUseTrkId: Switch between using TofPoints count or McTracks count 
              for the multiple source flag.
      ii)  MaxTimeDistClust: Maximal time distance between Digi pairs on adjacent 
              channels for which they are merged in the same cluster.
      iii) MaxSpaceDistClust: Maximal distance along strips between Digis pairs 
              on adjacent channels for which they are merged in the same cluster.
      
3) Usage hints
   a) Modify the input files in  macro/tof/digitizer/run_digi.C if you want to 
      run only the TOF digitizer or in macro/tof/digitizer/run_reco.C if you 
      want to run the full reconstruction chain (run_reco100.C has only STS+TOF)
   b) Prepare the digitizer options, most users will probably mainly be 
      interested in the following options:
      FeeGainSigma, FeeTotThr, TimeResElec
      TimeResStart
      ClusterModel (only "Flat disc" is currently reasonnably working)
      BeamInputFile (current file generated for 99% efficiency, nominal tof 
         system resolution and HD counter clusters properties)
      ClusterRadiusModel
   c) Prepare the clusterizer options
   d) Run the ROOT macro like the normal reco script
   e) Control histograms will appear in *.hst.root files, all other outputs are
      also in the same folder