Fix hundreds of std=c++11 compiler warningsAllow to change compiler settings in cmake/DD4hep.cmake valid for all packages.Watch out for CMAKE_CXX_FLAGS in cmake/DD4hep.cmake.Move to use Boost spirit::phoenix version 3. ---- Prepare for ROOT 6

Add component to allow the setup of the magnetic field tracking in Geant4 from python. See DDG4/examples/CLICSidSimu.py for the usage.

   -> added operators ==/!= for map<>::iterator

   over maps on macos 

First implementation of dipole field, HepMC reader for DDG4 and fix to import constants into DDG4 python

Improved version of MC particle handler, fix calorimeter hit aggregation with multiple contributions