message: Temp patch avioding compilation error
  operator= returning this for the moment. Avoid compilation
  error due to missing return value on some platforms.
diff: @@ -92,7 +92,7 @@ class VPart: public AliVParticle {
  public:
  VPart() : AliVParticle(), fMom(), fCharge(0) {;}
  VPart(const VPart &p) : AliVParticle(p), fMom(p.fMom), fCharge(p.fCharge) {;}
  - VPart& operator=(const VPart &p) {;}
  + VPart& operator=(const VPart &p) { return *this;}
  virtual ~VPart() {;}
  virtual Double_t Px() const {return 0;}
  virtual Double_t Py() const {return 0;}
  