Refactor some parts of the Architecture:

* JSON visitor are located in the format namespace
  * Visitor are *real* visitor
  * Visitable class has been renamed to Object
  * Due to a bug in Visual Studio 2015, we move to VS2017

api/python/PE/objects/pyCodeView.cpp

@@ -15,7 +15,7 @@
  */
 #include "pyPE.hpp"
 
-#include "LIEF/visitors/Hash.hpp"
+#include "LIEF/PE/hash.hpp"
 #include "LIEF/PE/CodeView.hpp"
 
 #include <string>
@@ -28,7 +28,7 @@ template<class T>
 using setter_t = void (CodeView::*)(T);
 
 void init_PE_CodeView_class(py::module& m) {
-  py::class_<CodeView>(m, "CodeView")
+  py::class_<CodeView, LIEF::Object>(m, "CodeView")
     .def_property_readonly("cv_signature",
         static_cast<getter_t<CODE_VIEW_SIGNATURES>>(&CodeView::cv_signature),
         "Type of the code view (" RST_CLASS_REF(lief.PE.CODE_VIEW_SIGNATURES) ")")
@@ -37,7 +37,7 @@ void init_PE_CodeView_class(py::module& m) {
     .def("__ne__", &CodeView::operator!=)
     .def("__hash__",
         [] (const CodeView& codeview) {
-          return LIEF::Hash::hash(codeview);
+          return Hash::hash(codeview);
         })
 
     .def("__str__", [] (const CodeView& cv)