Initialise variable for surface list
remove useless calls and comment argument name to avoid unused argument warning

pick the VolumeManager from lcdd, and create it if necessary instead of creating a static one in SurfaceHelper
This is necessary in case someone needs a volumemanger before surfaceHelper is called.

add map cellID of surface <--> vector of cellID of neighbouring surfaces for ZPlanar and ZPetalDisk data struct

Seperate internal/external implementation of segmentations. Remove some ID tags - do no longer make sense in git.

Fix DDDB examples. On request move Position, Rotations and transformations back to Geometry namespace.

Add DDRec/src/plugins to folders documented by doxygen

Add groups for plugins and some example
Add an entry in the main "Modules" part of the doxygen website so they are easily found.
And sub groups for different plugin types.
See changes in the plugins for example. The documentation in these changes is not complete.

   (affected ILD VXD)

 - used in dumpdetector:
   dumpdetector compact.xml -d 

 - fixed module id for calo barrel surfaces
 - ...

 - fixed issue w/ outer surface materials

    - ICone, VolConeImpl, VolCone, ConeSurface
    

  ( innerThickness, innerRadLength, etc)

   subclasses 

    - re-included implementations for CylinderSurface
      methods (u,v,nornaml,...)
    - use multi_map in SurfaceManager 
      -> transparent to code expecting map
      lookup but provideds all surfaces when
      iterating
    - fixed Surface::distance using localPoint

      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

Fixed Coil Rmin/Rmax swap bug in ILD/CLIC convert to Gear plugins. Also modified CMakeLists.txt to set CMAKE_INSTALL_PREFIX to source dir as before, rather than /usr