• The Visual Studio 2019 compiler, GCC 9.2 and Clang 9.0 where added to the CI configuration.
• Bugfix for #39, fs::rename on Windows didn't replace an axisting regular file as required by the standard, but gave an error. New tests and a fix as provided in the issue was implemented.
• Bugfix for #39, for the forwarding use via fs_fwd.hpp or fs_std_fwd.hpp der was a use of DWORD in the forwarding part leading to an error if Windows.h was not
  included before the header. The tests were changed to give an error in that case too and the useage of DWORD was removed.
• Bugfix for #38, casting the return value of GetProcAddress gave a warning with -Wcast-function-type on MSYS2 and MinGW GCC 9 builds.