Add test to dump hits from MultiSegment-MultiCollections example. Investigate issue: https://github.com/AIDASoft/DD4hep/issues/141 for details

   - note: this does not yet seemt to be filled by DDG4!

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

use map(string, string) to store parameter value pairs, declareProperty so we can pass it from python as a dict
call saveRun from endRun

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.

   such that other user actions can access it (e.g. for adding the MCParticle collection)