This also now allows to skip events

Require Geant 9.6 at CMAKE level
Replace "#pragma error" by "#error", because "#pragma error" is ignored as unknown

Macro needs string concatenation instead of quotation marks,
otherwise the plugin name comes out wrong

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 

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