...for Visual Studio 2010 and later, since we used to copy them and
merely update the value of $(VSVer) during 'make dist' as needed.
Instead of doing that, move the property sheets for Visual Studio 2010,
which is the base version that we use, into a directory of its own, and
make the Visual Studio 2010~2022 projects look for them in that
directory, and set VSVer according to the toolset version identified by
each of the project files.
The ARM64-specific property sheet needed for VS2017 and the VS2008
property sheets will remain as they are.
We can again use MSBuild trickery to do what was done in the dropped
property sheet.
Unfortunately, like the last commit, I couldn't figure out a way do to
something similar in the VS2008 project files... :|
... and so stop using gtk3-install.[vsprops|props], and remove that
property sheet from the dist and dist the NMake Makefile for the
purpose.
Also remove win32/vs10/gtk3-install.vcxproj.filters as well, as it is
no longer needed.
We will remove the gtk3-install.[vsprops|[props][.in] in a subsequent
commit.
This makes the rest of the sources that are generated being put in GDK's build
directory for the Visual Studio projects, instead of being placed in GDK's
source subdir, so that:
* We can avoid polluting GDK's source tree.
* The Visual Studio builds won't interfere with the Meson builds.
Update the project files to look for the generated sources and headers in the
right places, as well as making the introspection builds look for the generated
sources as well.
Also remove the gtk3-gen-srcs property sheets and put the relevant parts in the
corresponding gtk3-build-defines property sheets, to clean things up a bit.
