core: add getPyArrayType from Python helper

This is needed for Windows

include/eigenpy/numpy.hpp

@@ -40,11 +40,14 @@ namespace eigenpy
   EIGENPY_DLLEXPORT PyObject* call_PyArray_New(PyTypeObject * py_type_ptr, int nd, npy_intp * shape, int np_type, void * data_ptr, int options);
 
   EIGENPY_DLLEXPORT int call_PyArray_ObjectType(PyObject *, int);
+
+  EIGENPY_DLLEXPORT PyTypeObject getPyArrayType();
 }
 #else
   #define call_PyArray_SimpleNew PyArray_SimpleNew
   #define call_PyArray_New(py_type_ptr,nd,shape,np_type,data_ptr,options) \
     PyArray_New(py_type_ptr,nd,shape,np_type,NULL,data_ptr,0,options,NULL)
+  #define getPyArrayType() PyArray_Type
 #endif
 
 #endif // ifndef __eigenpy_numpy_hpp__

src/numpy.cpp

@@ -32,5 +32,7 @@ namespace eigenpy
     return PyArray_ObjectType(obj,val);
   }
 
+  PyTypeObject getPyArrayType() { return PyArray_Type; }
+
 #endif
 }