WIP: Initial example of python as script language from C++

Initial version to allow access to python functionality from the main C++ code.

This can be used for access to plotting function for e.g. realtime plots as well as code generation for heterogeneous systems. GPU Code for example needs several different implementations for optimal performance depending on the underlying hardware.

In addition, python can be changed during the runtime of Corsika without recompilation neccessary. This allows fast tests for kernel development.