More fixes for g4py requested by Thomas.
Move build of XercesC before build of Geant4, due it is needed for the build process of G4 gdml which is needed for FairShip.
Enable compilation of FairSoft with the clang compiler on Linux. Most changes are needed to get rid of the dependency to libstdc++.
Instead of this standard template library the new libc++ ist used. If one wants to compile with clang and libc++ on Linux the
correct installation of clang and libc++ is needed.

One can donwload a set of scripts to compile clang and libc++ on Linux from https://github.com/fuhlig1/usefull_scripts.

Build Boost with toolset clang independent of platform.
Compilation with clang and libc++ works now also on linux. There are still some libraries which have a dependency to libstdc++. This has to be solved properly.
Create more packages to get rid of libstdc++ dependencies.
Fix problem with Root VMC Makefiles used by geant3 and geant4_vmc. Now the files are compiled with libc++ and c++11 when compiling with Clang on Linux.
Patch to have correct path to libc++ in the Geant4 librariws when compiling on linux using clang.
New package which is needed to remove dependencies to stdc++ when compiling on linux using clang.
When compiling on linux using clang use the icu library from our installation.
New scripts to install opengl which is needed on linux with clang to get rid of libstdc++ dependencies.
Remove dependecies to libstdc++ when compiling with clang and libc++ on linux.
Remove all dependencies to libstdc++ when compiling with clang and libcxx on Linux.
Fix problem with TGeoManager and some CBM or Panda geometries.
Different LDFLAGS for Fortran due to problems with newer gfortran versions which don't tolerate the parameter -std=c++11.
Set LDFLAGS correctly. Remove dubug output.
Switch the root source code from downloading a tar file to using the git repository. Use a version from the branch 5-34-00-patches which was requested by Ship and CBM.
Add a file which lists all dependencies of FairSoft. In the file there are also the commands which are needed to install them using the package managers of the different Linux flavors.
Change installation script to cope with the new CMake version 3.0.0.
Add tests for programs which are only needed when compiling with clang on Linux. The tests are only executed in this case.
Fix configuration bugs.
If the found fortran compiler is f95, which is normaly only a link, use the program it points to as fortran compiler.
Create symbolic link from lib64 to lib in the installation directory.
Use specific version of geant4_vmc which support G4Root and is taken from the git repository.
After using readlink to get the real fortran compiler there was a problem with an if statement. The problem is now fixed.