Updating OpenFace to version 2.2.0 (#741)

Change log:

Moving to C++17. This means that the code can only be build using C++17 compilers (e.g. g++ >8 and Visual Studio 2017, clang > 5), fixing related bugs - (#698, #629, #641)
Removing an explicit dependency on boost (all the filesystem operations are performed using std::filesystem or boost::filesysteme). If boost is available it will used boost:filesystem, otherwise std::filesystem (this requires C++17)
Visual Studio 2017 is now the main version for Visual Studio builds, VS 2015 is no longer supported
Updating OpenCV to 4.1 version (#511)
Fixing a bug with output images when using GUI (#694)
Updating RAWImage - #609, so it can be initialized from System.Drawing.Bitmap directly
Fixing overlap detection for multi face tracking (#693)

lib/3rdParty/OpenCV/include/opencv2/gapi/util/util.hpp

@@ -0,0 +1,92 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+//
+// Copyright (C) 2018 Intel Corporation
+
+
+#ifndef OPENCV_GAPI_UTIL_HPP
+#define OPENCV_GAPI_UTIL_HPP
+
+#include <utility> // std::tuple
+
+// \cond HIDDEN_SYMBOLS
+// This header file contains some generic utility functions which are
+// used in other G-API Public API headers.
+//
+// PLEASE don't put any stuff here if it is NOT used in public API headers!
+
+namespace cv
+{
+namespace detail
+{
+    // Recursive integer sequence type, useful for enumerating elements of
+    // template parameter packs.
+    template<int... I> struct Seq     { using next = Seq<I..., sizeof...(I)>; };
+    template<int Sz>   struct MkSeq   { using type = typename MkSeq<Sz-1>::type::next; };
+    template<>         struct MkSeq<0>{ using type = Seq<>; };
+
+    // Checks if elements of variadic template satisfy the given Predicate.
+    // Implemented via tuple, with an interface to accept plain type lists
+    template<template<class> class, typename, typename...> struct all_satisfy;
+
+    template<template<class> class F, typename T, typename... Ts>
+    struct all_satisfy<F, std::tuple<T, Ts...> >
+    {
+        static const constexpr bool value = F<T>::value
+            && all_satisfy<F, std::tuple<Ts...> >::value;
+    };
+    template<template<class> class F, typename T>
+    struct all_satisfy<F, std::tuple<T> >
+    {
+        static const constexpr bool value = F<T>::value;
+    };
+
+    template<template<class> class F, typename T, typename... Ts>
+    struct all_satisfy: public all_satisfy<F, std::tuple<T, Ts...> > {};
+
+    // Permute given tuple type C with given integer sequence II
+    // Sequence may be less than tuple C size.
+    template<class, class> struct permute_tuple;
+
+    template<class C, int... IIs>
+    struct permute_tuple<C, Seq<IIs...> >
+    {
+        using type = std::tuple< typename std::tuple_element<IIs, C>::type... >;
+    };
+
+    // Given T..., generates a type sequence of sizeof...(T)-1 elements
+    // which is T... without its last element
+    // Implemented via tuple, with an interface to accept plain type lists
+    template<typename T, typename... Ts> struct all_but_last;
+
+    template<typename T, typename... Ts>
+    struct all_but_last<std::tuple<T, Ts...> >
+    {
+        using C    = std::tuple<T, Ts...>;
+        using S    = typename MkSeq<std::tuple_size<C>::value - 1>::type;
+        using type = typename permute_tuple<C, S>::type;
+    };
+
+    template<typename T, typename... Ts>
+    struct all_but_last: public all_but_last<std::tuple<T, Ts...> > {};
+
+    template<typename... Ts>
+    using all_but_last_t = typename all_but_last<Ts...>::type;
+
+    // NB.: This is here because there's no constexpr std::max in C++11
+    template<std::size_t S0, std::size_t... SS> struct max_of_t
+    {
+        static constexpr const std::size_t rest  = max_of_t<SS...>::value;
+        static constexpr const std::size_t value = rest > S0 ? rest : S0;
+    };
+    template<std::size_t S> struct max_of_t<S>
+    {
+        static constexpr const std::size_t value = S;
+    };
+} // namespace detail
+} // namespace cv
+
+// \endcond
+
+#endif //  OPENCV_GAPI_UTIL_HPP