[WIP]New python api

[pradal]

Do not merge yet. This branch is shared between @pfernique @pradal and @guedon

[pradal]

I have a build error:

In file included from build-scons/src/py/wrapper/wrapper_d3fbcd4a393754ca8d7be71823564225.cpp:1:
In file included from build-scons/src/py/wrapper/_stat_tool.h:4:
In file included from /Users/pradal/miniconda2/envs/autowig/include/boost/python.hpp:11:
In file included from /Users/pradal/miniconda2/envs/autowig/include/boost/python/args.hpp:25:
In file included from /Users/pradal/miniconda2/envs/autowig/include/boost/python/object_core.hpp:14:
In file included from /Users/pradal/miniconda2/envs/autowig/include/boost/python/call.hpp:15:
In file included from /Users/pradal/miniconda2/envs/autowig/include/boost/python/converter/arg_to_python.hpp:10:
In file included from /Users/pradal/miniconda2/envs/autowig/include/boost/python/to_python_indirect.hpp:10:
In file included from /Users/pradal/miniconda2/envs/autowig/include/boost/python/object/pointer_holder.hpp:61:
In file included from /Users/pradal/miniconda2/envs/autowig/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:57:
/Users/pradal/miniconda2/envs/autowig/include/boost/python/object/pointer_holder.hpp:188:19: error: no matching constructor for initialization of 'std::__1::vector<stat_tool::discrete_parametric, std::__1::allocator<stat_tool::discrete_parametric> >'
        : m_p(new Value(
                  ^

[pfernique]

This should resolve the error. These errors are due to std classes that are implemented differently on Linux, OsX and Windows.