Open requested to merge danyeaw/pygobject:add-dll-dir into master
This upstreams a patch from gvsbuild. In Python 3.8, a new os.add_dll_directory method was added to make loading DLLs in Windows more consistent. The impact of this is that even if I compile GTK successfully with MSVC, and add it to the Path, INCLUDE, and LIB, I am still not able to pip install PyGObject in Windows. This closes #545 by finding the first GTK DLL location from the Windows PATH variable.