Use of std deprecated code in C++17 in MSCV 2017

[r.undheim@…]

In Microsoft Visual C++ 2017 you have the possibility to compile with C++17 enabled. (Have to enable this to be able to use std::optional). This give a lot of warnings for deprecated stuff. The std::allocator<void> is deprecated (​http://en.cppreference.com/w/cpp/memory/allocator) and the std::result_of has changed to std::invoke_result (​http://en.cppreference.com/w/cpp/types/result_of). I compile with treat warning as errors, so this make is difficult to use the asio library.