- Fix wrapping of GC ops/funcs according to policy described in bug #1045.
- Remove ValidateGC/ValidatePictures on the redirected drawables/pictures
    -- it's not needed, and DDXs shouldn't be seeing redirected drawables
    in render or GC ops/funcs when cw is running.
- Mark all GC/Picture state as dirty when moving from redirected to
    non-redirected, since it hadn't been passed down in Change* or
    Validate* while redirected.
- Remove CreatePicture wrapper that didn't do anything.
- Comment on why AddTraps wrapper isn't needed.