Geant4Output2LCIO: Use event and run number offset also in the case of presence of input event parameters extension

Geant4Output2LCIO: get LCIO input event parameters from dedicated event extension (if exists) and write them to LCIO output event

Added run and event number offsets to start counting runs and events from a different value than 0. Added float, int and string event parameters to class properties allowing a steering from outside

Improve the CMS example. Add word for the raw generator status of generator particles to Geant4Particle

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)