Use a new structure s_attack to hold attack stuffs in s_anim. Now you can give each frame a hitflash, hitsound.
Change follow-up logic in do_attack, so if a follow up is performed, the attack checking is over(previous code just had some problems when checking energy cost and hitsound). Now hitsound of previous animation will be played, and followup's energycost value wont be used anymore.
