I added a version.hpp and updated the version.py so that
one can find the version of the library either from the
c++ or the python (if there is python support).
modified: CMakeLists.txt
modified: cmake/TRIQSConfig.cmake.in
modified: pytriqs/version.py.in
modified: triqs/CMakeLists.txt
new file: triqs/version.hpp.in