- updated release notes
   - increased version number
   - set DD4HEP_USE_CXX11 ON

Caution please. Do not update nor use this relase until green light comes. For details please see doc/release.notes.

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

      a polymorphic pointer of type VolSurfaceBase
      - this should facilitate the creation
        of dedicated surface classes for special cases
        such as inside the beampipe or the face of the calorimeter

 - updated release notes

   - release notes and versions

   Markus in release   ----------------- v00-12 -------

Needed to access cell dimensions in a segmentation agnostic way
Implemented unit tests for cellDimensions
Implemented default function throwing exception
Implemented cellDimensions for CartesianGridXY, XZ, YZ, XZY
Added c++11 definition to DD4hep.cmake (implemented functions with and without c++11)