Support for multi-threaded Geant4 applications using DDG4Details are described in the release notes.

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

No code changes. Common code formatting removing tabs, replacing with spaces (tab-size=-2) + emacs reformatting.

Phi2 is the deltaPhi in Geant4, it is the EndPhi in TGeo

Hopefully I got the assemblies right now. Assembly test added in examples/ClientTests. Please see also doc/release.notes

    object to instantiate a G4VSensitiveDetector 
    class
    ->  allows to use pre-existing SD classes 
    -> changed macro DECLARE_SENSITIVEDETECTOR to
       create a factory, thus replace:
       //    typedef Geant4GenericSD<TrackerCombine>  Geant4TrackerCombine;
       typedef SimpleG4SDFactory< Geant4GenericSD<TrackerCombine> >  Geant4TrackerCombine;

   in copyNrs

   bool   runDaughterVisibilityWorkaround
   ( change value in code)