[VECGEOM-161]:An attempt to make SafetySqr for Box in Implementation.
Please check the code before merge. I found a delay and gdb showed some problem DistanceToOut:----
(gdb) bt
#0 0x00000000004d6bce in UBox::DistanceToOut(vecgeom::cxx::Vector3D const&, vecgeom::cxx::Vector3D const&, vecgeom::cxx::Vector3D&, bool&, double) const ()
#1 0x00002aaab459f681 in G4USolid::DistanceToOut (this=, pt=..., d=..., calcNorm=, validNorm=0x0, norm=0x0)
at /opt/Sources/GEANT_IV/geant4.10.01/source/geometry/management/src/G4USolid.cc:142
#2 0x00000000004821f0 in vecgeom::Benchmarker::RunToOutGeant4(double*, double*) ()
#3 0x000000000048f9da in vecgeom::Benchmarker::RunToOutBenchmark() ()
#4 0x00000000004904b2 in vecgeom::Benchmarker::RunBenchmark() ()
#5 0x0000000000436b34 in main ()