Only link against DD4hepG4 if Geant4 is used. Create list of libraries to link
against based on the build options.

    - in a next step the SurfaceManager will
      be re-written to be a singleton that
      caches surface lists and maps ...

Fixes for warnings from doxygen
proper list layout
verbatim around xml examples
escape unknown tag
remove copy/pasted doc for non-existent parameter

Add example segmentation and document parameters for setGridRValues and setGridPhiValues

Moved the position tag from being inside the shape enviroment (x_shape) to the global x_det enviroment.
Otherwise there is a conflict between DetectorAssembly and Subtraction/UnionSolid since both read the same tag.

  - create CalorimeterParameters for all ILD calos
    if LayeredCalorimeterData extension is present

   - som code reformatting

   -> drivers can call this method also w/o defining a shape
      for the envelope

some missing characters
missmatch in function signatures due to using std::string

Fix: phi/theta Coordinate calculation was not updating the cellID
     Create protected functions no taking cellIDs, make public functions update the cellID for the decoder
     Make position update the cellID for the decoder and use the private phi/theta functions

Fix: Change type for thetaBins and phiBins members, they should be integer (at least the setters only allowed int)

Tweaks: Use CellID instead of long64 (same typedef)

* protect against self assignment
* delete NULL is a no-op, don't need to check

Create stringstream to avoid changing output format for cout

now phi bins are counted from the offset counter-clockwise up

use scientific format for float/double
correct the unsigned long and long format output (l is length specifier)

a) This (the one in Handle.h) is used to pass parameters to the Segmentations at the moment
b) I know 30 digits is overkill

 Update teveDisplay for better visualization resolution on Tube. For example TPC, Hcal outer shape and Coil.

Don't convert units when calling the setDimension internal function.
Otherwise conversion is applied twice when setDimensions calls _setDimensions

    Geometry::Volume createPlacedEnvelope( DD4hep::Geometry::LCDD& lcdd, DD4hep::XML::Handle_t e , DD4hep::Geometry::DetElement sdet ) ;

   shapes (subtraction, union or intersection ) 

This also now allows to skip events

   to be used to only build detector envelopes
 - fixed visualization in teve_display to also
   show the envelope volume
 - visualize daughter level in dumpdetector (tabs)