Like the autotools builds of the introspection files, don't include gtkx.h
in the introspection prepropcessing as it should not be included by other
GTK+ headers.
The a11y headers are now listed with the main Makefile.am of GTK, and
GDK introduced deprecated headers, so we need to account for them for the
build of the introspection files.
Add support to build the introspection files for GdkWin32, as done recently
in the autotools builds and clean up the NMake Makefile for building the
introspection files a bit.
For some reason, gdk_win32_display_manager_get_type() was not exported in
gdk-3.0.lib, force its export, so that the GdkWin32-3.0.gir can be built
properly with the Visual C++ builds. This is a known problem that some
symbols in static libraries that are linked into a DLL in Visual C++, even
if they were marked with __declspec(dllexport) via _GDK_EXTERN.
The current approach of building the introspection files for GTK works, but
is often cumbersome as one needs to set many environmental variables before
launching a solution file, which runs a Windows batch script to generate
the .gir/.typelib files. It was also possible to hand-run the batch script
from the Visual Studio command prompt, but even more environmental
variables need to be set.
This changes the approach to build the introspection files using an NMake
Makefile (but elimating from the Visual Studio Project Files the part to
build the introspection files) to:
-Make it clearer to the person building the introspection files what
environmental variables are needed, specifically for PKG_CONFIG_PATH and
MINGWDIR and CFG (formerly CONF). Setting stuff like VSVER, PLAT and BASEDIR
is no longer required, which was a bit clunky.
-Allows some more easier flexibility on the build of the intropsection files.
