Infrastructure change: game_anim_length and game_flash_length now

both get passed a pointer to the game_ui. This means that if they
need to note down information for the redraw function about what
_type_ of flash or animation is required, they now have somewhere to
do so.

git-svn-id: svn://svn.tartarus.org/sgt/puzzles@5858 cda61777-01e9-0310-a592-d414129be87e