- in particular CLHEP is now added to the library path
     if geant4 was built with external CLHEP

    the tests after initializing w/ thisdd4hep.sh

Add missing include directories. They are needed when compiling a clean checkout of dd4hep with testing. As the headers are not installed previously they are not found otherwise.

  - created new test for testing units (to be extended)
  - added config file for publishing test results at
    http://aidasoft.desy.de/CDash/index.php
  - added README
  

   - no real tests so far

Added simple nearest neighbour calculation
Fixed compact XML of all examples to work with the new segmentation types

- DDSegmenation now comes with its own factory and with generic access to segmentation parameters
- Removes the necessity of implementing different XML parsers in DDCore
- DD4hep::Segmentation becomes a lot simpler and its Object is now following a standard decorator pattern, completely removing any need of messing with the vtable
- compact2lcdd works for example with BarrelCalorimeter from CLICSiD example (other examples need to adapt their XML to valid segmentation names)
- See also examples/Segmentation/SegmentationTest for stand alone example
- The segmentation names and their parameter names do NOT follow current SLIC conventions. Once SLIC depends on DDSegmentation this will work transparently.