Use the normal effect system for fullscreen effects. This allows effects
that are implemented via shaders to be used, such as the blind effects
which are used frequently in Daibanchou.
- Create separate directories for source and header files.
- Build code shared between xsystem4 and aindump as a static library.
- Create header dirs gfx/ system4/ and vm/
- Make CG.c/h usable without a running VM