GNOME Builds for MSVC

The following libraries are built:

• the gtk bundle: everything inside https://gitlab.gnome.org/GNOME/gtk.git
• gobject-introspection: prerequisite for librsvg (optional) and libadwaita
• libxml2: prerequisite for librsvg and therefore pixbufloader-svg.dll
• librsvg: necessary for pixbufloader-svg.dll, used by GTK to load scalable icons
• libadwaita: building blocks for modern GNOME applications

The following libraries are planned:

• adwaita-icon-theme: Mostly private use system icons