IN THcDriftChamber.cxx :
  1)   Moved hardcoding of Yplane plane number to Addplane since it is called
     before ReadDatabase
  2) In FindEasySpacePoint add variable max_dist to match the code in
     h_find_easy_space_point.f more and fix problem
  3) As in h_find_easy_space_point  use max_dist instead
     of FSpacePointCriterion in IF statement to pick matching "x" hits.
In THCDC.h
  1) Set GetPicth and GetCentralWire as Double_t
  2) Set  GetSpacePointCriterion to return fSpace_Point_Criterion2[chamber-1]
     instead of sqrt
Replace some fixed length arrays with std::vector.  (Ole's suggestion)
Change space point from a structure to a full class
  THcDriftChamber::SpacePoint -> THcSpacePoint
  That way space points can be put in a TClonesArray and be made known
  to THcDC when stub information is added.
Merge branch 'develop' of hallcgit:hcana into develop