This is a stub-only library that can be used while building against
MSVC and contains no i18n machinery at all.
The dependencies added indirectly use the libintl.h header, and when
built as a subproject, the header won't be in a path known the
pre-processor.
Disable gio tests on Windows, fix .gitignore to not ignore
config.h.meson, and add more things to it.
Rename the library file naming and versioning to match what Autotools
outputs, e.g., libglib-2.0.so.0.5000.2 on Linux, libglib-2.0-0.dll and
glib-2.0-0.dll on Windows with MSVC.
Several more tiny fixes, more executables built and installed, install
pkg-config and m4 files, fix building of gobject tests.
Changes to gdbus-codegen to support out-of-tree builds without
environment variables set (which you can't in Meson). We now add the
build directory to the Python module search path.