Use the scripts that we have to copy the 2010 projects and updating
the various items in the project files to make them Visual Studio
2019-compatible upon 'make dist'.
Also ensure that the introspection NMake Makefiles can properly detect
that we are building with Visual Studio 2019.
The build/win32/detectenv-msvc.mak needs to be updated for Visual Studio
2017, and we ought to add quotes to surround the copy destination path
for the introspection files, so that we do not bail out in the copy
process (cmd.exe's copy command does not like '+' in them that are not
quoted).
This first adds a common autotools module that can be included by
the Makefile.am's to generate the file lists and the g-ir-scanner/
g-ir-compiler command lines to build the introspection files.
The autotools files for gdk/ and gtk/ are then updated to generate
the full file lists needed to build the introspection files, with
the full command lines for g-ir-scanner and g-ir-compiler as NMake
Makefile modules that can be used to build the introspection files
for Visual Studio builds.
https://bugzilla.gnome.org/show_bug.cgi?id=765195
